/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/FontPropertyTypes.h"
#include "mozilla/image/ImageMemoryReporter.h"
#include "mozilla/layers/CompositorManagerChild.h"
#include "mozilla/layers/CompositorThread.h"
#include "mozilla/layers/ImageBridgeChild.h"
#include "mozilla/layers/ISurfaceAllocator.h"     // for GfxMemoryImageReporter
#include "mozilla/webrender/RenderThread.h"
#include "mozilla/webrender/WebRenderAPI.h"
#include "mozilla/webrender/webrender_ffi.h"
#include "mozilla/layers/PaintThread.h"
#include "mozilla/gfx/gfxVars.h"
#include "mozilla/gfx/GPUProcessManager.h"
#include "mozilla/gfx/GraphicsMessages.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/Telemetry.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/Unused.h"

#include "mozilla/Logging.h"
#include "mozilla/Services.h"
#include "nsAppDirectoryServiceDefs.h"

#include "gfxCrashReporterUtils.h"
#include "gfxPlatform.h"
#include "gfxPrefs.h"
#include "gfxEnv.h"
#include "gfxTextRun.h"
#include "gfxUserFontSet.h"
#include "gfxConfig.h"
#include "VRProcessManager.h"
#include "VRThread.h"

#ifdef XP_WIN
#include <process.h>
#define getpid _getpid
#else
#include <unistd.h>
#endif

#include "nsXULAppAPI.h"
#include "nsDirectoryServiceUtils.h"
#include "nsDirectoryServiceDefs.h"

#if defined(XP_WIN)
#include "gfxWindowsPlatform.h"
#elif defined(XP_MACOSX)
#include "gfxPlatformMac.h"
#include "gfxQuartzSurface.h"
#include "nsCocoaFeatures.h"
#elif defined(MOZ_WIDGET_GTK)
#include "gfxPlatformGtk.h"
#elif defined(ANDROID)
#include "gfxAndroidPlatform.h"
#endif

#ifdef XP_WIN
#include <windows.h>
#include "mozilla/WindowsVersion.h"
#include "mozilla/gfx/DeviceManagerDx.h"
#endif

#include "nsGkAtoms.h"
#include "gfxPlatformFontList.h"
#include "gfxContext.h"
#include "gfxImageSurface.h"
#include "nsUnicodeProperties.h"
#include "harfbuzz/hb.h"
#include "gfxGraphiteShaper.h"
#include "gfx2DGlue.h"
#include "gfxGradientCache.h"
#include "gfxUtils.h" // for NextPowerOfTwo
#include "gfxFontMissingGlyphs.h"

#include "nsExceptionHandler.h"
#include "nsUnicodeRange.h"
#include "nsServiceManagerUtils.h"
#include "nsTArray.h"
#include "nsIObserverService.h"
#include "nsIScreenManager.h"
#include "FrameMetrics.h"
#include "MainThreadUtils.h"

#include "nsWeakReference.h"

#include "cairo.h"
#include "qcms.h"

#include "imgITools.h"

#include "plstr.h"
#include "nsCRT.h"
#include "GLContext.h"
#include "GLContextProvider.h"
#include "mozilla/gfx/Logging.h"

#ifdef USE_SKIA
# ifdef __GNUC__
#  pragma GCC diagnostic push
#  pragma GCC diagnostic ignored "-Wshadow"
# endif
# include "skia/include/core/SkGraphics.h"
# ifdef USE_SKIA_GPU
#  include "skia/include/gpu/GrContext.h"
#  include "skia/include/gpu/gl/GrGLInterface.h"
#  include "SkiaGLGlue.h"
# endif
# ifdef MOZ_ENABLE_FREETYPE
#  include "skia/include/ports/SkTypeface_cairo.h"
# endif
# include "mozilla/gfx/SkMemoryReporter.h"
# ifdef __GNUC__
#  pragma GCC diagnostic pop // -Wshadow
# endif
static const uint32_t kDefaultGlyphCacheSize = -1;

#endif

#if !defined(USE_SKIA) || !defined(USE_SKIA_GPU)
class mozilla::gl::SkiaGLGlue : public GenericAtomicRefCounted {
};
#endif

#include "mozilla/Preferences.h"
#include "mozilla/Assertions.h"
#include "mozilla/Atomics.h"
#include "mozilla/Attributes.h"
#include "mozilla/Mutex.h"

#include "nsAlgorithm.h"
#include "nsIGfxInfo.h"
#include "nsIXULRuntime.h"
#include "VsyncSource.h"
#include "SoftwareVsyncSource.h"
#include "nscore.h" // for NS_FREE_PERMANENT_DATA
#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/TouchEvent.h"
#include "gfxVR.h"
#include "VRManagerChild.h"
#include "mozilla/gfx/GPUParent.h"
#include "mozilla/layers/MemoryReportingMLGPU.h"
#include "prsystem.h"

namespace mozilla {
namespace layers {
void ShutdownTileCache();
} // namespace layers
} // namespace mozilla

using namespace mozilla;
using namespace mozilla::layers;
using namespace mozilla::gl;
using namespace mozilla::gfx;

gfxPlatform *gPlatform = nullptr;
static bool gEverInitialized = false;

const ContentDeviceData* gContentDeviceInitData = nullptr;

static Mutex* gGfxPlatformPrefsLock = nullptr;

// These two may point to the same profile
static qcms_profile *gCMSOutputProfile = nullptr;
static qcms_profile *gCMSsRGBProfile = nullptr;

static bool gCMSRGBTransformFailed = false;
static qcms_transform *gCMSRGBTransform = nullptr;
static qcms_transform *gCMSInverseRGBTransform = nullptr;
static qcms_transform *gCMSRGBATransform = nullptr;

static bool gCMSInitialized = false;
static eCMSMode gCMSMode = eCMSMode_Off;

static void ShutdownCMS();

#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/SourceSurfaceCairo.h"
using namespace mozilla::gfx;

/* Class to listen for pref changes so that chrome code can dynamically
   force sRGB as an output profile. See Bug #452125. */
class SRGBOverrideObserver final : public nsIObserver,
                                   public nsSupportsWeakReference
{
    ~SRGBOverrideObserver() = default;
public:
    NS_DECL_ISUPPORTS
    NS_DECL_NSIOBSERVER
};

/// This override of the LogForwarder, initially used for the critical graphics
/// errors, is sending the log to the crash annotations as well, but only
/// if the capacity set with the method below is >= 2.  We always retain the
/// very first critical message, and the latest capacity-1 messages are
/// rotated through. Note that we don't expect the total number of times
/// this gets called to be large - it is meant for critical errors only.

class CrashStatsLogForwarder: public mozilla::gfx::LogForwarder
{
public:
  explicit CrashStatsLogForwarder(CrashReporter::Annotation aKey);
  void Log(const std::string& aString) override;
  void CrashAction(LogReason aReason) override;
  bool UpdateStringsVector(const std::string& aString) override;

  LoggingRecord LoggingRecordCopy() override;

  void SetCircularBufferSize(uint32_t aCapacity);

private:
  // Helper for the Log()
  void UpdateCrashReport();

private:
  LoggingRecord mBuffer;
  CrashReporter::Annotation mCrashCriticalKey;
  uint32_t mMaxCapacity;
  int32_t mIndex;
  Mutex mMutex;
};

CrashStatsLogForwarder::CrashStatsLogForwarder(CrashReporter::Annotation aKey)
  : mBuffer()
  , mCrashCriticalKey(aKey)
  , mMaxCapacity(0)
  , mIndex(-1)
  , mMutex("CrashStatsLogForwarder")
{
}

void CrashStatsLogForwarder::SetCircularBufferSize(uint32_t aCapacity)
{
  MutexAutoLock lock(mMutex);

  mMaxCapacity = aCapacity;
  mBuffer.reserve(static_cast<size_t>(aCapacity));
}

LoggingRecord
CrashStatsLogForwarder::LoggingRecordCopy()
{
  MutexAutoLock lock(mMutex);
  return mBuffer;
}

bool
CrashStatsLogForwarder::UpdateStringsVector(const std::string& aString)
{
  // We want at least the first one and the last one.  Otherwise, no point.
  if (mMaxCapacity < 2) {
    return false;
  }

  mIndex += 1;
  MOZ_ASSERT(mIndex >= 0);

  // index will count 0, 1, 2, ..., max-1, 1, 2, ..., max-1, 1, 2, ...
  int32_t index = mIndex ? (mIndex-1) % (mMaxCapacity-1) + 1 : 0;
  MOZ_ASSERT(index >= 0 && index < (int32_t)mMaxCapacity);
  MOZ_ASSERT(index <= mIndex && index <= (int32_t)mBuffer.size());

  double tStamp = (TimeStamp::NowLoRes() - TimeStamp::ProcessCreation()).ToSecondsSigDigits();

  // Checking for index >= mBuffer.size(), rather than index == mBuffer.size()
  // just out of paranoia, but we know index <= mBuffer.size().
  LoggingRecordEntry newEntry(mIndex,aString,tStamp);
  if (index >= static_cast<int32_t>(mBuffer.size())) {
    mBuffer.push_back(newEntry);
  } else {
    mBuffer[index] = newEntry;
  }
  return true;
}

void CrashStatsLogForwarder::UpdateCrashReport()
{
  std::stringstream message;
  std::string logAnnotation;

  switch (XRE_GetProcessType()) {
  case GeckoProcessType_Default:
    logAnnotation = "|[";
    break;
  case GeckoProcessType_Content:
    logAnnotation = "|[C";
    break;
  case GeckoProcessType_GPU:
    logAnnotation = "|[G";
    break;
  default:
    logAnnotation = "|[X";
    break;
  }

  for (auto& it : mBuffer) {
    message << logAnnotation << Get<0>(it) << "]" << Get<1>(it) << " (t=" << Get<2>(it) << ") ";
  }

  nsCString reportString(message.str().c_str());
  nsresult annotated = CrashReporter::AnnotateCrashReport(mCrashCriticalKey,
                                                          reportString);

  if (annotated != NS_OK) {
    printf("Crash Annotation %s: %s",
           CrashReporter::AnnotationToString(mCrashCriticalKey),
           message.str().c_str());
  }
}

class LogForwarderEvent : public Runnable
{
  ~LogForwarderEvent() override = default;

public:
  NS_INLINE_DECL_REFCOUNTING_INHERITED(LogForwarderEvent, Runnable)

  explicit LogForwarderEvent(const nsCString& aMessage)
    : mozilla::Runnable("LogForwarderEvent")
    , mMessage(aMessage)
  {
  }

  NS_IMETHOD Run() override {
    MOZ_ASSERT(NS_IsMainThread() && (XRE_IsContentProcess() || XRE_IsGPUProcess()));

    if (XRE_IsContentProcess()) {
      dom::ContentChild* cc = dom::ContentChild::GetSingleton();
      Unused << cc->SendGraphicsError(mMessage);
    } else if (XRE_IsGPUProcess()) {
      GPUParent* gp = GPUParent::GetSingleton();
      Unused << gp->SendGraphicsError(mMessage);
    }

    return NS_OK;
  }

protected:
  nsCString mMessage;
};

void CrashStatsLogForwarder::Log(const std::string& aString)
{
  MutexAutoLock lock(mMutex);

  if (UpdateStringsVector(aString)) {
    UpdateCrashReport();
  }

  // Add it to the parent strings
  if (!XRE_IsParentProcess()) {
    nsCString stringToSend(aString.c_str());
    if (NS_IsMainThread()) {
      if (XRE_IsContentProcess()) {
        dom::ContentChild* cc = dom::ContentChild::GetSingleton();
        Unused << cc->SendGraphicsError(stringToSend);
      } else if (XRE_IsGPUProcess()) {
        GPUParent* gp = GPUParent::GetSingleton();
        Unused << gp->SendGraphicsError(stringToSend);
      }
    } else {
      nsCOMPtr<nsIRunnable> r1 = new LogForwarderEvent(stringToSend);
      NS_DispatchToMainThread(r1);
    }
  }
}

class CrashTelemetryEvent : public Runnable
{
  ~CrashTelemetryEvent() override = default;

public:
  NS_INLINE_DECL_REFCOUNTING_INHERITED(CrashTelemetryEvent, Runnable)

  explicit CrashTelemetryEvent(uint32_t aReason)
    : mozilla::Runnable("CrashTelemetryEvent")
    , mReason(aReason)
  {
  }

  NS_IMETHOD Run() override {
    MOZ_ASSERT(NS_IsMainThread());
    Telemetry::Accumulate(Telemetry::GFX_CRASH, mReason);
    return NS_OK;
  }

protected:
  uint32_t mReason;
};

void
CrashStatsLogForwarder::CrashAction(LogReason aReason)
{
#ifndef RELEASE_OR_BETA
  // Non-release builds crash by default, but will use telemetry
  // if this environment variable is present.
  static bool useTelemetry = gfxEnv::GfxDevCrashTelemetry();
#else
  // Release builds use telemetry by default, but will crash instead
  // if this environment variable is present.
  static bool useTelemetry = !gfxEnv::GfxDevCrashMozCrash();
#endif

  if (useTelemetry) {
    // The callers need to assure that aReason is in the range
    // that the telemetry call below supports.
    if (NS_IsMainThread()) {
      Telemetry::Accumulate(Telemetry::GFX_CRASH, (uint32_t)aReason);
    } else {
      nsCOMPtr<nsIRunnable> r1 = new CrashTelemetryEvent((uint32_t)aReason);
      NS_DispatchToMainThread(r1);
    }
  } else {
    // ignoring aReason, we can get the information we need from the stack
    MOZ_CRASH("GFX_CRASH");
  }
}

NS_IMPL_ISUPPORTS(SRGBOverrideObserver, nsIObserver, nsISupportsWeakReference)

#define GFX_DOWNLOADABLE_FONTS_ENABLED "gfx.downloadable_fonts.enabled"

#define GFX_PREF_FALLBACK_USE_CMAPS  "gfx.font_rendering.fallback.always_use_cmaps"

#define GFX_PREF_OPENTYPE_SVG "gfx.font_rendering.opentype_svg.enabled"

#define GFX_PREF_WORD_CACHE_CHARLIMIT "gfx.font_rendering.wordcache.charlimit"
#define GFX_PREF_WORD_CACHE_MAXENTRIES "gfx.font_rendering.wordcache.maxentries"

#define GFX_PREF_GRAPHITE_SHAPING "gfx.font_rendering.graphite.enabled"

#define BIDI_NUMERAL_PREF "bidi.numeral"

#define GFX_PREF_CMS_FORCE_SRGB "gfx.color_management.force_srgb"

#define FONT_VARIATIONS_PREF "layout.css.font-variations.enabled"

NS_IMETHODIMP
SRGBOverrideObserver::Observe(nsISupports *aSubject,
                              const char *aTopic,
                              const char16_t* someData)
{
    NS_ASSERTION(NS_strcmp(someData,
                           (u"" GFX_PREF_CMS_FORCE_SRGB)) == 0,
                 "Restarting CMS on wrong pref!");
    ShutdownCMS();
    // Update current cms profile.
    gfxPlatform::CreateCMSOutputProfile();
    return NS_OK;
}

static const char* kObservedPrefs[] = {
    "gfx.downloadable_fonts.",
    "gfx.font_rendering.",
    BIDI_NUMERAL_PREF,
    nullptr
};

static void
FontPrefChanged(const char* aPref, void* aData)
{
    MOZ_ASSERT(aPref);
    NS_ASSERTION(gfxPlatform::GetPlatform(), "the singleton instance has gone");
    gfxPlatform::GetPlatform()->FontsPrefsChanged(aPref);
}

void
gfxPlatform::OnMemoryPressure(layers::MemoryPressureReason aWhy)
{
    Factory::PurgeAllCaches();
    gfxGradientCache::PurgeAllCaches();
    gfxFontMissingGlyphs::Purge();
    PurgeSkiaFontCache();
    PurgeSkiaGPUCache();
    if (XRE_IsParentProcess()) {
      layers::CompositorManagerChild* manager = CompositorManagerChild::GetInstance();
      if (manager) {
        manager->SendNotifyMemoryPressure();
      }
    }
}

gfxPlatform::gfxPlatform()
  : mHasVariationFontSupport(false)
  , mAzureCanvasBackendCollector(this, &gfxPlatform::GetAzureBackendInfo)
  , mApzSupportCollector(this, &gfxPlatform::GetApzSupportInfo)
  , mTilesInfoCollector(this, &gfxPlatform::GetTilesSupportInfo)
  , mCompositorBackend(layers::LayersBackend::LAYERS_NONE)
  , mScreenDepth(0)
{
    mAllowDownloadableFonts = UNINITIALIZED_VALUE;
    mFallbackUsesCmaps = UNINITIALIZED_VALUE;

    mWordCacheCharLimit = UNINITIALIZED_VALUE;
    mWordCacheMaxEntries = UNINITIALIZED_VALUE;
    mGraphiteShapingEnabled = UNINITIALIZED_VALUE;
    mOpenTypeSVGEnabled = UNINITIALIZED_VALUE;
    mBidiNumeralOption = UNINITIALIZED_VALUE;

    mSkiaGlue = nullptr;

    InitBackendPrefs(GetBackendPrefs());

    mTotalSystemMemory = PR_GetPhysicalMemorySize();

    VRManager::ManagerInit();
}

gfxPlatform*
gfxPlatform::GetPlatform()
{
    if (!gPlatform) {
        MOZ_RELEASE_ASSERT(!XRE_IsContentProcess(),
                           "Content Process should have called InitChild() before first GetPlatform()");
        Init();
    }
    return gPlatform;
}

bool
gfxPlatform::Initialized()
{
  return !!gPlatform;
}

/* static */ void
gfxPlatform::InitChild(const ContentDeviceData& aData)
{
  MOZ_ASSERT(XRE_IsContentProcess());
  MOZ_RELEASE_ASSERT(!gPlatform,
                     "InitChild() should be called before first GetPlatform()");
  // Make the provided initial ContentDeviceData available to the init
  // routines, so they don't have to do a sync request from the parent.
  gContentDeviceInitData = &aData;
  Init();
  gContentDeviceInitData = nullptr;
}

void RecordingPrefChanged(const char *aPrefName, void *aClosure)
{
  if (Preferences::GetBool("gfx.2d.recording", false)) {
    nsAutoCString fileName;
    nsAutoString prefFileName;
    nsresult rv = Preferences::GetString("gfx.2d.recordingfile", prefFileName);
    if (NS_SUCCEEDED(rv)) {
      CopyUTF16toUTF8(prefFileName, fileName);
    } else {
      nsCOMPtr<nsIFile> tmpFile;
      if (NS_FAILED(NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(tmpFile)))) {
        return;
      }
      fileName.AppendPrintf("moz2drec_%i_%i.aer", XRE_GetProcessType(), getpid());

      nsresult rv = tmpFile->AppendNative(fileName);
      if (NS_FAILED(rv))
        return;

#ifdef XP_WIN
      rv = tmpFile->GetPath(prefFileName);
      CopyUTF16toUTF8(prefFileName, fileName);
#else
      rv = tmpFile->GetNativePath(fileName);
#endif
      if (NS_FAILED(rv))
        return;
    }

#ifdef XP_WIN
    gPlatform->mRecorder = Factory::CreateEventRecorderForFile(prefFileName.BeginReading());
#else
    gPlatform->mRecorder = Factory::CreateEventRecorderForFile(fileName.BeginReading());
#endif
    printf_stderr("Recording to %s\n", fileName.get());
    Factory::SetGlobalEventRecorder(gPlatform->mRecorder);
  } else {
    Factory::SetGlobalEventRecorder(nullptr);
  }
}

#define WR_DEBUG_PREF "gfx.webrender.debug"

void
WebRenderDebugPrefChangeCallback(const char* aPrefName, void*)
{
  int32_t flags = 0;
#define GFX_WEBRENDER_DEBUG(suffix, bit)                          \
  if (Preferences::GetBool(WR_DEBUG_PREF suffix, false)) {        \
    flags |= (bit);                                             \
  }

  // TODO: It would be nice to get the bit patterns directly from the rust code.
  GFX_WEBRENDER_DEBUG(".profiler",           1 << 0)
  GFX_WEBRENDER_DEBUG(".render-targets",     1 << 1)
  GFX_WEBRENDER_DEBUG(".texture-cache",      1 << 2)
  GFX_WEBRENDER_DEBUG(".gpu-time-queries",   1 << 3)
  GFX_WEBRENDER_DEBUG(".gpu-sample-queries", 1 << 4)
  GFX_WEBRENDER_DEBUG(".disable-batching",   1 << 5)
  GFX_WEBRENDER_DEBUG(".epochs",             1 << 6)
  GFX_WEBRENDER_DEBUG(".compact-profiler",   1 << 7)
  GFX_WEBRENDER_DEBUG(".echo-driver-messages", 1 << 8)
  GFX_WEBRENDER_DEBUG(".new-frame-indicator", 1 << 9)
  GFX_WEBRENDER_DEBUG(".new-scene-indicator", 1 << 10)
  GFX_WEBRENDER_DEBUG(".show-overdraw", 1 << 11)
#undef GFX_WEBRENDER_DEBUG

  gfx::gfxVars::SetWebRenderDebugFlags(flags);
}


#if defined(USE_SKIA)
static uint32_t GetSkiaGlyphCacheSize()
{
    // Only increase font cache size on non-android to save memory.
#if !defined(MOZ_WIDGET_ANDROID)
    // 10mb as the default pref cache size on desktop due to talos perf tweaking.
    // Chromium uses 20mb and skia default uses 2mb.
    // We don't need to change the font cache count since we usually
    // cache thrash due to asian character sets in talos.
    // Only increase memory on the content process
    uint32_t cacheSize = gfxPrefs::SkiaContentFontCacheSize() * 1024 * 1024;
    if (mozilla::BrowserTabsRemoteAutostart()) {
      return XRE_IsContentProcess() ? cacheSize : kDefaultGlyphCacheSize;
    }

    return cacheSize;
#else
    return kDefaultGlyphCacheSize;
#endif // MOZ_WIDGET_ANDROID
}
#endif

class WebRenderMemoryReporter final : public nsIMemoryReporter {
public:
  NS_DECL_ISUPPORTS
  NS_DECL_NSIMEMORYREPORTER

private:
  ~WebRenderMemoryReporter() = default;
};

// Memory reporter for WebRender.
//
// The reporting within WebRender is manual and incomplete. We could do a much
// more thorough job by depending on the malloc_size_of crate, but integrating
// that into WebRender is tricky [1].
//
// So the idea is to start with manual reporting for the large allocations
// detected by DMD, and see how much that can cover in practice (which may
// require a few rounds of iteration). If that approach turns out to be
// fundamentally insufficient, we can either duplicate more of the malloc_size_of
// functionality in WebRender, or deal with the complexity of a gecko-only
// crate dependency.
//
// [1] See https://bugzilla.mozilla.org/show_bug.cgi?id=1480293#c1
struct WebRenderMemoryReporterHelper {
  WebRenderMemoryReporterHelper(nsIHandleReportCallback* aCallback, nsISupports* aData)
    : mCallback(aCallback), mData(aData)
  {}
  nsCOMPtr<nsIHandleReportCallback> mCallback;
  nsCOMPtr<nsISupports> mData;

  void Report(size_t aBytes, const char* aName) const
  {
    nsPrintfCString path("explicit/gfx/webrender/%s", aName);
    nsCString desc(NS_LITERAL_CSTRING("CPU heap memory used by WebRender"));
    ReportInternal(aBytes, path, desc, nsIMemoryReporter::KIND_HEAP);
  }

  void ReportTexture(size_t aBytes, const char* aName) const
  {
    nsPrintfCString path("gfx/webrender/textures/%s", aName);
    nsCString desc(NS_LITERAL_CSTRING("GPU texture memory used by WebRender"));
    ReportInternal(aBytes, path, desc, nsIMemoryReporter::KIND_OTHER);
  }

  void ReportInternal(size_t aBytes, nsACString& aPath, nsACString& aDesc, int32_t aKind) const
  {
    // Generally, memory reporters pass the empty string as the process name to
    // indicate "current process". However, if we're using a GPU process, the
    // measurements will actually take place in that process, and it's easier to
    // just note that here rather than trying to invoke the memory reporter in
    // the GPU process.
    nsAutoCString processName;
    if (gfxConfig::IsEnabled(Feature::GPU_PROCESS)) {
      GPUParent::GetGPUProcessName(processName);
    }

    mCallback->Callback(processName, aPath,
                        aKind, nsIMemoryReporter::UNITS_BYTES,
                        aBytes, aDesc, mData);
  }
};

static void
FinishAsyncMemoryReport()
{
  nsCOMPtr<nsIMemoryReporterManager> imgr =
    do_GetService("@mozilla.org/memory-reporter-manager;1");
  if (imgr) {
    imgr->EndReport();
  }
}

NS_IMPL_ISUPPORTS(WebRenderMemoryReporter, nsIMemoryReporter)

NS_IMETHODIMP
WebRenderMemoryReporter::CollectReports(nsIHandleReportCallback* aHandleReport,
                                        nsISupports* aData, bool aAnonymize)
{
  MOZ_ASSERT(XRE_IsParentProcess());
  MOZ_ASSERT(NS_IsMainThread());
  layers::CompositorManagerChild* manager = CompositorManagerChild::GetInstance();
  if (!manager) {
    FinishAsyncMemoryReport();
    return NS_OK;
  }

  WebRenderMemoryReporterHelper helper(aHandleReport, aData);
  manager->SendReportMemory(
    [=](wr::MemoryReport aReport) {
      // CPU Memory.
      helper.Report(aReport.primitive_stores, "primitive-stores");
      helper.Report(aReport.clip_stores, "clip-stores");
      helper.Report(aReport.gpu_cache_metadata, "gpu-cache/metadata");
      helper.Report(aReport.gpu_cache_cpu_mirror, "gpu-cache/cpu-mirror");
      helper.Report(aReport.render_tasks, "render-tasks");
      helper.Report(aReport.hit_testers, "hit-testers");
      helper.Report(aReport.fonts, "resource-cache/fonts");
      helper.Report(aReport.images, "resource-cache/images");
      helper.Report(aReport.rasterized_blobs, "resource-cache/rasterized-blobs");

      // GPU Memory.
      helper.ReportTexture(aReport.gpu_cache_textures, "gpu-cache");
      helper.ReportTexture(aReport.vertex_data_textures, "vertex-data");
      helper.ReportTexture(aReport.render_target_textures, "render-targets");
      helper.ReportTexture(aReport.texture_cache_textures, "texture-cache");

      FinishAsyncMemoryReport();
    },
    [](mozilla::ipc::ResponseRejectReason aReason) {
      FinishAsyncMemoryReport();
    }
  );

  return NS_OK;
}


void
gfxPlatform::Init()
{
    MOZ_RELEASE_ASSERT(!XRE_IsGPUProcess(), "GFX: Not allowed in GPU process.");
    MOZ_RELEASE_ASSERT(NS_IsMainThread(), "GFX: Not in main thread.");

    if (gEverInitialized) {
        MOZ_CRASH("Already started???");
    }
    gEverInitialized = true;

    // Initialize the preferences by creating the singleton.
    gfxPrefs::GetSingleton();
    gfxVars::Initialize();

    gfxConfig::Init();

    if (XRE_IsParentProcess() || recordreplay::IsRecordingOrReplaying()) {
      GPUProcessManager::Initialize();

      if (Preferences::GetBool("media.wmf.skip-blacklist")) {
        gfxVars::SetPDMWMFDisableD3D11Dlls(nsCString());
        gfxVars::SetPDMWMFDisableD3D9Dlls(nsCString());
      } else {
        nsAutoCString d3d11;
        Preferences::GetCString("media.wmf.disable-d3d11-for-dlls", d3d11);
        gfxVars::SetPDMWMFDisableD3D11Dlls(d3d11);
        nsAutoCString d3d9;
        Preferences::GetCString("media.wmf.disable-d3d9-for-dlls", d3d9);
        gfxVars::SetPDMWMFDisableD3D9Dlls(d3d9);
      }

      nsCOMPtr<nsIFile> file;
      nsresult rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(file));
      if (NS_FAILED(rv)) {
        gfxVars::SetGREDirectory(nsString());
      } else {
        nsAutoString path;
        file->GetPath(path);
        gfxVars::SetGREDirectory(nsString(path));
      }
    }

    // Drop a note in the crash report if we end up forcing an option that could
    // destabilize things.  New items should be appended at the end (of an existing
    // or in a new section), so that we don't have to know the version to interpret
    // these cryptic strings.
    {
      nsAutoCString forcedPrefs;
      // D2D prefs
      forcedPrefs.AppendPrintf("FP(D%d%d",
                               gfxPrefs::Direct2DDisabled(),
                               gfxPrefs::Direct2DForceEnabled());
      // Layers prefs
      forcedPrefs.AppendPrintf("-L%d%d%d%d",
                               gfxPrefs::LayersAMDSwitchableGfxEnabled(),
                               gfxPrefs::LayersAccelerationDisabledDoNotUseDirectly(),
                               gfxPrefs::LayersAccelerationForceEnabledDoNotUseDirectly(),
                               gfxPrefs::LayersD3D11ForceWARP());
      // WebGL prefs
      forcedPrefs.AppendPrintf("-W%d%d%d%d%d%d%d%d",
                               gfxPrefs::WebGLANGLEForceD3D11(),
                               gfxPrefs::WebGLANGLEForceWARP(),
                               gfxPrefs::WebGLDisabled(),
                               gfxPrefs::WebGLDisableANGLE(),
                               gfxPrefs::WebGLDXGLEnabled(),
                               gfxPrefs::WebGLForceEnabled(),
                               gfxPrefs::WebGLForceLayersReadback(),
                               gfxPrefs::WebGLForceMSAA());
      // Prefs that don't fit into any of the other sections
      forcedPrefs.AppendPrintf("-T%d%d%d) ",
                               gfxPrefs::AndroidRGB16Force(),
                               gfxPrefs::CanvasAzureAccelerated(),
                               gfxPrefs::ForceShmemTiles());
      ScopedGfxFeatureReporter::AppNote(forcedPrefs);
    }

    InitMoz2DLogging();

    gGfxPlatformPrefsLock = new Mutex("gfxPlatform::gGfxPlatformPrefsLock");

    /* Initialize the GfxInfo service.
     * Note: we can't call functions on GfxInfo that depend
     * on gPlatform until after it has been initialized
     * below. GfxInfo initialization annotates our
     * crash reports so we want to do it before
     * we try to load any drivers and do device detection
     * incase that code crashes. See bug #591561. */
    nsCOMPtr<nsIGfxInfo> gfxInfo;
    /* this currently will only succeed on Windows */
    gfxInfo = services::GetGfxInfo();

#if defined(XP_WIN)
    gPlatform = new gfxWindowsPlatform;
#elif defined(XP_MACOSX)
    gPlatform = new gfxPlatformMac;
#elif defined(MOZ_WIDGET_GTK)
    gPlatform = new gfxPlatformGtk;
#elif defined(ANDROID)
    gPlatform = new gfxAndroidPlatform;
#else
    #error "No gfxPlatform implementation available"
#endif
    gPlatform->InitAcceleration();
    gPlatform->InitWebRenderConfig();
    gPlatform->InitOMTPConfig();

    if (gfxConfig::IsEnabled(Feature::GPU_PROCESS)) {
      GPUProcessManager* gpu = GPUProcessManager::Get();
      gpu->LaunchGPUProcess();
    }

    if (XRE_IsParentProcess() || recordreplay::IsRecordingOrReplaying()) {
      if (gfxPlatform::ForceSoftwareVsync()) {
        gPlatform->mVsyncSource = (gPlatform)->gfxPlatform::CreateHardwareVsyncSource();
      } else {
        gPlatform->mVsyncSource = gPlatform->CreateHardwareVsyncSource();
      }
    }

#ifdef USE_SKIA
    SkGraphics::Init();
#  ifdef MOZ_ENABLE_FREETYPE
    SkInitCairoFT(gPlatform->FontHintingEnabled());
#  endif
#endif

    InitLayersIPC();

    gPlatform->PopulateScreenInfo();
    gPlatform->ComputeTileSize();

#ifdef MOZ_ENABLE_FREETYPE
    Factory::SetFTLibrary(gPlatform->GetFTLibrary());
#endif

    gPlatform->mHasVariationFontSupport =
        gPlatform->CheckVariationFontSupport();

    nsresult rv;
    rv = gfxPlatformFontList::Init();
    if (NS_FAILED(rv)) {
        MOZ_CRASH("Could not initialize gfxPlatformFontList");
    }

    gPlatform->mScreenReferenceSurface =
        gPlatform->CreateOffscreenSurface(IntSize(1, 1),
                                          SurfaceFormat::A8R8G8B8_UINT32);
    if (!gPlatform->mScreenReferenceSurface) {
        MOZ_CRASH("Could not initialize mScreenReferenceSurface");
    }

    gPlatform->mScreenReferenceDrawTarget =
        gPlatform->CreateOffscreenContentDrawTarget(IntSize(1, 1),
                                                    SurfaceFormat::B8G8R8A8);
    if (!gPlatform->mScreenReferenceDrawTarget ||
        !gPlatform->mScreenReferenceDrawTarget->IsValid()) {
      // If TDR is detected, create a draw target with software backend
      // and it should be replaced later when the process gets the device
      // reset notification.
      if (!gPlatform->DidRenderingDeviceReset()) {
        gfxCriticalError() << "Could not initialize mScreenReferenceDrawTarget";
      }
    }

    rv = gfxFontCache::Init();
    if (NS_FAILED(rv)) {
        MOZ_CRASH("Could not initialize gfxFontCache");
    }

    /* Create and register our CMS Override observer. */
    gPlatform->mSRGBOverrideObserver = new SRGBOverrideObserver();
    Preferences::AddWeakObserver(gPlatform->mSRGBOverrideObserver, GFX_PREF_CMS_FORCE_SRGB);

    Preferences::RegisterPrefixCallbacks(FontPrefChanged, kObservedPrefs);

    GLContext::PlatformStartup();

    Preferences::RegisterCallbackAndCall(RecordingPrefChanged, "gfx.2d.recording");

    CreateCMSOutputProfile();

    // Listen to memory pressure event so we can purge DrawTarget caches
    gPlatform->mMemoryPressureObserver = layers::MemoryPressureObserver::Create(gPlatform);

    // Request the imgITools service, implicitly initializing ImageLib.
    nsCOMPtr<imgITools> imgTools = do_GetService("@mozilla.org/image/tools;1");
    if (!imgTools) {
      MOZ_CRASH("Could not initialize ImageLib");
    }

    RegisterStrongMemoryReporter(new GfxMemoryImageReporter());
    if (XRE_IsParentProcess() && gfxVars::UseWebRender()) {
      RegisterStrongAsyncMemoryReporter(new WebRenderMemoryReporter());
    }

#ifdef USE_SKIA
    RegisterStrongMemoryReporter(new SkMemoryReporter());
#endif
    mlg::InitializeMemoryReporters();

#ifdef USE_SKIA
    uint32_t skiaCacheSize = GetSkiaGlyphCacheSize();
    if (skiaCacheSize != kDefaultGlyphCacheSize) {
      SkGraphics::SetFontCacheLimit(skiaCacheSize);
    }
#endif

    InitNullMetadata();
    InitOpenGLConfig();

    if (XRE_IsParentProcess()) {
      gfxVars::SetDXInterop2Blocked(IsDXInterop2Blocked());
      gfxVars::SetDXNV12Blocked(IsDXNV12Blocked());
      Preferences::Unlock(FONT_VARIATIONS_PREF);
      if (!gPlatform->HasVariationFontSupport()) {
        // Ensure variation fonts are disabled and the pref is locked.
        Preferences::SetBool(FONT_VARIATIONS_PREF, false,
                             PrefValueKind::Default);
        Preferences::SetBool(FONT_VARIATIONS_PREF, false);
        Preferences::Lock(FONT_VARIATIONS_PREF);
      }

      nsCOMPtr<nsIFile> profDir;
      rv = NS_GetSpecialDirectory(NS_APP_PROFILE_DIR_STARTUP, getter_AddRefs(profDir));
      if (NS_FAILED(rv)) {
        gfxVars::SetProfDirectory(nsString());
      } else {
        nsAutoString path;
        profDir->GetPath(path);
        gfxVars::SetProfDirectory(nsString(path));
      }

      gfxUtils::RemoveShaderCacheFromDiskIfNecessary();
    }

    nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
    if (obs) {
      obs->NotifyObservers(nullptr, "gfx-features-ready", nullptr);
    }
}

/* static*/ bool
gfxPlatform::IsDXInterop2Blocked()
{
  nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
  nsCString blockId;
  int32_t status;
  if (!NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_DX_INTEROP2,
                                              blockId, &status))) {
    return true;
  }
  return status != nsIGfxInfo::FEATURE_STATUS_OK;
}

/* static*/ bool
gfxPlatform::IsDXNV12Blocked()
{
  nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
  nsCString blockId;
  int32_t status;
  if (!NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_DX_NV12,
                                              blockId, &status))) {
    return true;
  }
  return status != nsIGfxInfo::FEATURE_STATUS_OK;
}

/* static */ int32_t
gfxPlatform::MaxTextureSize()
{
  // Make sure we don't completely break rendering because of a typo in the
  // pref or whatnot.
  const int32_t kMinSizePref = 2048;
  return std::max(kMinSizePref, gfxPrefs::MaxTextureSizeDoNotUseDirectly());
}

/* static */ int32_t
gfxPlatform::MaxAllocSize()
{
  // Make sure we don't completely break rendering because of a typo in the
  // pref or whatnot.
  const int32_t kMinAllocPref = 10000000;
  return std::max(kMinAllocPref, gfxPrefs::MaxAllocSizeDoNotUseDirectly());
}

/* static */ void
gfxPlatform::InitMoz2DLogging()
{
  auto fwd = new CrashStatsLogForwarder(
    CrashReporter::Annotation::GraphicsCriticalError);
  fwd->SetCircularBufferSize(gfxPrefs::GfxLoggingCrashLength());

  mozilla::gfx::Config cfg;
  cfg.mLogForwarder = fwd;
  cfg.mMaxTextureSize = gfxPlatform::MaxTextureSize();
  cfg.mMaxAllocSize = gfxPlatform::MaxAllocSize();

  gfx::Factory::Init(cfg);
}

/* static */ bool
gfxPlatform::IsHeadless()
{
    static bool initialized = false;
    static bool headless = false;
    if (!initialized) {
      initialized = true;
      headless = PR_GetEnv("MOZ_HEADLESS");
    }
    return headless;
}

static bool sLayersIPCIsUp = false;

/* static */ void
gfxPlatform::InitNullMetadata()
{
  ScrollMetadata::sNullMetadata = new ScrollMetadata();
  ClearOnShutdown(&ScrollMetadata::sNullMetadata);
}

void
gfxPlatform::Shutdown()
{
    // In some cases, gPlatform may not be created but Shutdown() called,
    // e.g., during xpcshell tests.
    if (!gPlatform) {
      return;
    }

    MOZ_ASSERT(!sLayersIPCIsUp);

    // These may be called before the corresponding subsystems have actually
    // started up. That's OK, they can handle it.
    gfxFontCache::Shutdown();
    gfxGradientCache::Shutdown();
    gfxAlphaBoxBlur::ShutdownBlurCache();
    gfxGraphiteShaper::Shutdown();
    gfxPlatformFontList::Shutdown();
    gfxFontMissingGlyphs::Shutdown();
    ShutdownTileCache();

    // Free the various non-null transforms and loaded profiles
    ShutdownCMS();

    /* Unregister our CMS Override callback. */
    NS_ASSERTION(gPlatform->mSRGBOverrideObserver, "mSRGBOverrideObserver has alreay gone");
    Preferences::RemoveObserver(gPlatform->mSRGBOverrideObserver, GFX_PREF_CMS_FORCE_SRGB);
    gPlatform->mSRGBOverrideObserver = nullptr;

    Preferences::UnregisterPrefixCallbacks(FontPrefChanged, kObservedPrefs);

    NS_ASSERTION(gPlatform->mMemoryPressureObserver, "mMemoryPressureObserver has already gone");
    if (gPlatform->mMemoryPressureObserver) {
      gPlatform->mMemoryPressureObserver->Unregister();
      gPlatform->mMemoryPressureObserver = nullptr;
    }
    gPlatform->mSkiaGlue = nullptr;

    if (XRE_IsParentProcess()) {
      gPlatform->mVsyncSource->Shutdown();
    }

    gPlatform->mVsyncSource = nullptr;

    // Shut down the default GL context provider.
    GLContextProvider::Shutdown();

#if defined(XP_WIN)
    // The above shutdown calls operate on the available context providers on
    // most platforms.  Windows is a "special snowflake", though, and has three
    // context providers available, so we have to shut all of them down.
    // We should only support the default GL provider on Windows; then, this
    // could go away. Unfortunately, we currently support WGL (the default) for
    // WebGL on Optimus.
    GLContextProviderEGL::Shutdown();
#endif

    if (XRE_IsParentProcess()) {
      GPUProcessManager::Shutdown();
      VRProcessManager::Shutdown();
    }

    gfx::Factory::ShutDown();

    delete gGfxPlatformPrefsLock;

    gfxVars::Shutdown();
    gfxPrefs::DestroySingleton();
    gfxFont::DestroySingletons();

    gfxConfig::Shutdown();

    gPlatform->WillShutdown();

    delete gPlatform;
    gPlatform = nullptr;
}

/* static */ void
gfxPlatform::InitLayersIPC()
{
  if (sLayersIPCIsUp) {
    return;
  }
  sLayersIPCIsUp = true;

  if (XRE_IsContentProcess()) {
    if (gfxVars::UseOMTP() && !recordreplay::IsRecordingOrReplaying()) {
      layers::PaintThread::Start();
    }
  }

  if (XRE_IsParentProcess() || recordreplay::IsRecordingOrReplaying()) {
    if (!gfxConfig::IsEnabled(Feature::GPU_PROCESS) && gfxVars::UseWebRender()) {
      wr::RenderThread::Start();
      image::ImageMemoryReporter::InitForWebRender();
    }

    layers::CompositorThreadHolder::Start();
    gfx::VRListenerThreadHolder::Start();
  }
}

/* static */ void
gfxPlatform::ShutdownLayersIPC()
{
    if (!sLayersIPCIsUp) {
      return;
    }
    sLayersIPCIsUp = false;

    if (XRE_IsContentProcess()) {
        gfx::VRManagerChild::ShutDown();
        // cf bug 1215265.
        if (gfxPrefs::ChildProcessShutdown()) {
          layers::CompositorManagerChild::Shutdown();
          layers::ImageBridgeChild::ShutDown();
        }

        if (gfxVars::UseOMTP() && !recordreplay::IsRecordingOrReplaying()) {
          layers::PaintThread::Shutdown();
        }
    } else if (XRE_IsParentProcess()) {
        gfx::VRManagerChild::ShutDown();
        layers::CompositorManagerChild::Shutdown();
        layers::ImageBridgeChild::ShutDown();
        // This has to happen after shutting down the child protocols.
        layers::CompositorThreadHolder::Shutdown();
        gfx::VRListenerThreadHolder::Shutdown();
        image::ImageMemoryReporter::ShutdownForWebRender();
        // There is a case that RenderThread exists when gfxVars::UseWebRender() is false.
        // This could happen when WebRender was fallbacked to compositor.
        if (wr::RenderThread::Get()) {
          wr::RenderThread::ShutDown();

          Preferences::UnregisterCallback(WebRenderDebugPrefChangeCallback, WR_DEBUG_PREF);
        }

    } else {
      // TODO: There are other kind of processes and we should make sure gfx
      // stuff is either not created there or shut down properly.
    }
}

void
gfxPlatform::WillShutdown()
{
    // Destoy these first in case they depend on backend-specific resources.
    // Otherwise, the backend's destructor would be called before the
    // base gfxPlatform destructor.
    mScreenReferenceSurface = nullptr;
    mScreenReferenceDrawTarget = nullptr;
}

gfxPlatform::~gfxPlatform()
{
    // The cairo folks think we should only clean up in debug builds,
    // but we're generally in the habit of trying to shut down as
    // cleanly as possible even in production code, so call this
    // cairo_debug_* function unconditionally.
    //
    // because cairo can assert and thus crash on shutdown, don't do this in release builds
#ifdef NS_FREE_PERMANENT_DATA
#ifdef USE_SKIA
    // must do Skia cleanup before Cairo cleanup, because Skia may be referencing
    // Cairo objects e.g. through SkCairoFTTypeface
    SkGraphics::PurgeFontCache();
#endif

#if MOZ_TREE_CAIRO
    cairo_debug_reset_static_data();
#endif
#endif
}

/* static */ already_AddRefed<DrawTarget>
gfxPlatform::CreateDrawTargetForSurface(gfxASurface *aSurface, const IntSize& aSize)
{
  SurfaceFormat format = aSurface->GetSurfaceFormat();
  RefPtr<DrawTarget> drawTarget = Factory::CreateDrawTargetForCairoSurface(aSurface->CairoSurface(), aSize, &format);
  if (!drawTarget) {
    gfxWarning() << "gfxPlatform::CreateDrawTargetForSurface failed in CreateDrawTargetForCairoSurface";
    return nullptr;
  }
  return drawTarget.forget();
}

cairo_user_data_key_t kSourceSurface;

/**
 * Record the backend that was used to construct the SourceSurface.
 * When getting the cached SourceSurface for a gfxASurface/DrawTarget pair,
 * we check to make sure the DrawTarget's backend matches the backend
 * for the cached SourceSurface, and only use it if they match. This
 * can avoid expensive and unnecessary readbacks.
 */
struct SourceSurfaceUserData
{
  RefPtr<SourceSurface> mSrcSurface;
  BackendType mBackendType;
};

void SourceBufferDestroy(void *srcSurfUD)
{
  delete static_cast<SourceSurfaceUserData*>(srcSurfUD);
}

UserDataKey kThebesSurface;

struct DependentSourceSurfaceUserData
{
  RefPtr<gfxASurface> mSurface;
};

void SourceSurfaceDestroyed(void *aData)
{
  delete static_cast<DependentSourceSurfaceUserData*>(aData);
}

void
gfxPlatform::ClearSourceSurfaceForSurface(gfxASurface *aSurface)
{
  aSurface->SetData(&kSourceSurface, nullptr, nullptr);
}

/* static */ already_AddRefed<SourceSurface>
gfxPlatform::GetSourceSurfaceForSurface(RefPtr<DrawTarget> aTarget,
                                        gfxASurface* aSurface,
                                        bool aIsPlugin)
{
  if (!aSurface->CairoSurface() || aSurface->CairoStatus()) {
    return nullptr;
  }

  if (!aTarget) {
    aTarget = gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
  }

  void *userData = aSurface->GetData(&kSourceSurface);

  if (userData) {
    SourceSurfaceUserData *surf = static_cast<SourceSurfaceUserData*>(userData);

    if (surf->mSrcSurface->IsValid() && surf->mBackendType == aTarget->GetBackendType()) {
      RefPtr<SourceSurface> srcSurface(surf->mSrcSurface);
      return srcSurface.forget();
    }
    // We can just continue here as when setting new user data the destroy
    // function will be called for the old user data.
  }

  SurfaceFormat format = aSurface->GetSurfaceFormat();

  if (aTarget->GetBackendType() == BackendType::CAIRO) {
    // If we're going to be used with a CAIRO DrawTarget, then just create a
    // SourceSurfaceCairo since we don't know the underlying type of the CAIRO
    // DrawTarget and can't pick a better surface type. Doing this also avoids
    // readback of aSurface's surface into memory if, for example, aSurface
    // wraps an xlib cairo surface (which can be important to avoid a major
    // slowdown).
    //
    // We return here regardless of whether CreateSourceSurfaceFromNativeSurface
    // succeeds or not since we don't expect to be able to do any better below
    // if it fails.
    //
    // Note that the returned SourceSurfaceCairo holds a strong reference to
    // the cairo_surface_t* that it wraps, which essencially means it holds a
    // strong reference to aSurface since aSurface shares its
    // cairo_surface_t*'s reference count variable. As a result we can't cache
    // srcBuffer on aSurface (see below) since aSurface would then hold a
    // strong reference back to srcBuffer, creating a reference loop and a
    // memory leak. Not caching is fine since wrapping is cheap enough (no
    // copying) so we can just wrap again next time we're called.
    return Factory::CreateSourceSurfaceForCairoSurface(aSurface->CairoSurface(),
                                                       aSurface->GetSize(), format);
  }

  RefPtr<SourceSurface> srcBuffer;

  // Currently no other DrawTarget types implement CreateSourceSurfaceFromNativeSurface

  if (!srcBuffer) {
    // If aSurface wraps data, we can create a SourceSurfaceRawData that wraps
    // the same data, then optimize it for aTarget:
    RefPtr<DataSourceSurface> surf = GetWrappedDataSourceSurface(aSurface);
    if (surf) {
      srcBuffer = aIsPlugin ? aTarget->OptimizeSourceSurfaceForUnknownAlpha(surf)
                            : aTarget->OptimizeSourceSurface(surf);

      if (srcBuffer == surf) {
        // GetWrappedDataSourceSurface returns a SourceSurface that holds a
        // strong reference to aSurface since it wraps aSurface's data and
        // needs it to stay alive. As a result we can't cache srcBuffer on
        // aSurface (below) since aSurface would then hold a strong reference
        // back to srcBuffer, creating a reference loop and a memory leak. Not
        // caching is fine since wrapping is cheap enough (no copying) so we
        // can just wrap again next time we're called.
        //
        // Note that the check below doesn't catch this since srcBuffer will be a
        // SourceSurfaceRawData object (even if aSurface is not a gfxImageSurface
        // object), which is why we need this separate check.
        return srcBuffer.forget();
      }
    }
  }

  if (!srcBuffer) {
    MOZ_ASSERT(aTarget->GetBackendType() != BackendType::CAIRO,
               "We already tried CreateSourceSurfaceFromNativeSurface with a "
               "DrawTargetCairo above");
    // We've run out of performant options. We now try creating a SourceSurface
    // using a temporary DrawTargetCairo and then optimizing it to aTarget's
    // actual type. The CreateSourceSurfaceFromNativeSurface() call will
    // likely create a DataSourceSurface (possibly involving copying and/or
    // readback), and the OptimizeSourceSurface may well copy again and upload
    // to the GPU. So, while this code path is rarely hit, hitting it may be
    // very slow.
    srcBuffer = Factory::CreateSourceSurfaceForCairoSurface(aSurface->CairoSurface(),
                                                            aSurface->GetSize(), format);
    if (srcBuffer) {
      srcBuffer = aTarget->OptimizeSourceSurface(srcBuffer);
    }
  }

  if (!srcBuffer) {
    return nullptr;
  }

  if ((srcBuffer->GetType() == SurfaceType::CAIRO &&
       static_cast<SourceSurfaceCairo*>(srcBuffer.get())->GetSurface() ==
         aSurface->CairoSurface()) ||
      (srcBuffer->GetType() == SurfaceType::CAIRO_IMAGE &&
       static_cast<DataSourceSurfaceCairo*>(srcBuffer.get())->GetSurface() ==
         aSurface->CairoSurface())) {
    // See the "Note that the returned SourceSurfaceCairo..." comment above.
    return srcBuffer.forget();
  }

  // Add user data to aSurface so we can cache lookups in the future.
  auto *srcSurfUD = new SourceSurfaceUserData;
  srcSurfUD->mBackendType = aTarget->GetBackendType();
  srcSurfUD->mSrcSurface = srcBuffer;
  aSurface->SetData(&kSourceSurface, srcSurfUD, SourceBufferDestroy);

  return srcBuffer.forget();
}

already_AddRefed<DataSourceSurface>
gfxPlatform::GetWrappedDataSourceSurface(gfxASurface* aSurface)
{
  RefPtr<gfxImageSurface> image = aSurface->GetAsImageSurface();
  if (!image) {
    return nullptr;
  }
  RefPtr<DataSourceSurface> result =
    Factory::CreateWrappingDataSourceSurface(image->Data(),
                                             image->Stride(),
                                             image->GetSize(),
                                             ImageFormatToSurfaceFormat(image->Format()));

  if (!result) {
    return nullptr;
  }

  // If we wrapped the underlying data of aSurface, then we need to add user data
  // to make sure aSurface stays alive until we are done with the data.
  auto *srcSurfUD = new DependentSourceSurfaceUserData;
  srcSurfUD->mSurface = aSurface;
  result->AddUserData(&kThebesSurface, srcSurfUD, SourceSurfaceDestroyed);

  return result.forget();
}

void
gfxPlatform::ComputeTileSize()
{
  // The tile size should be picked in the parent processes
  // and sent to the child processes over IPDL GetTileSize.
  if (!XRE_IsParentProcess()) {
    return;
  }

  int32_t w = gfxPrefs::LayersTileWidth();
  int32_t h = gfxPrefs::LayersTileHeight();

  if (gfxPrefs::LayersTilesAdjust()) {
    gfx::IntSize screenSize = GetScreenSize();
    if (screenSize.width > 0) {
      // Choose a size so that there are between 2 and 4 tiles per screen width.
      // FIXME: we should probably make sure this is within the max texture size,
      // but I think everything should at least support 1024
      w = h = clamped(int32_t(RoundUpPow2(screenSize.width)) / 4, 256, 1024);
    }
  }

  // Don't allow changing the tile size after we've set it.
  // Right now the code assumes that the tile size doesn't change.
  MOZ_ASSERT(gfxVars::TileSize().width == -1 &&
             gfxVars::TileSize().height == -1);

  gfxVars::SetTileSize(IntSize(w, h));
}

void
gfxPlatform::PopulateScreenInfo()
{
  nsCOMPtr<nsIScreenManager> manager = do_GetService("@mozilla.org/gfx/screenmanager;1");
  MOZ_ASSERT(manager, "failed to get nsIScreenManager");

  nsCOMPtr<nsIScreen> screen;
  manager->GetPrimaryScreen(getter_AddRefs(screen));
  if (!screen) {
    // This can happen in xpcshell, for instance
    return;
  }

  screen->GetColorDepth(&mScreenDepth);
  if (XRE_IsParentProcess()) {
    gfxVars::SetScreenDepth(mScreenDepth);
  }

  int left, top;
  screen->GetRect(&left, &top, &mScreenSize.width, &mScreenSize.height);
}

bool
gfxPlatform::SupportsAzureContentForDrawTarget(DrawTarget* aTarget)
{
  if (!aTarget || !aTarget->IsValid()) {
    return false;
  }

#ifdef USE_SKIA_GPU
 // Skia content rendering doesn't support GPU acceleration, so we can't
 // use the same backend if the current backend is accelerated.
 if ((aTarget->GetType() == DrawTargetType::HARDWARE_RASTER)
     && (aTarget->GetBackendType() ==  BackendType::SKIA))
 {
  return false;
 }
#endif

  return SupportsAzureContentForType(aTarget->GetBackendType());
}

bool gfxPlatform::AllowOpenGLCanvas()
{
  // For now, only allow Skia+OpenGL, unless it's blocked.
  // Allow acceleration on Skia if the preference is set, unless it's blocked
  // as long as we have the accelerated layers

  // The compositor backend is only set correctly in the parent process,
  // so we let content process always assume correct compositor backend.
  // The callers have to do the right thing.
  bool correctBackend = !XRE_IsParentProcess() ||
    ((mCompositorBackend == LayersBackend::LAYERS_OPENGL ||
      mCompositorBackend == LayersBackend::LAYERS_WR) &&
     (GetContentBackendFor(mCompositorBackend) == BackendType::SKIA));

  if (gfxPrefs::CanvasAzureAccelerated() && correctBackend) {
    nsCOMPtr<nsIGfxInfo> gfxInfo = do_GetService("@mozilla.org/gfx/info;1");
    int32_t status;
    nsCString discardFailureId;
    return !gfxInfo ||
      (NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_CANVAS2D_ACCELERATION,
                                              discardFailureId,
                                              &status)) &&
       status == nsIGfxInfo::FEATURE_STATUS_OK);
  }
  return false;
}

void
gfxPlatform::InitializeSkiaCacheLimits()
{
  if (AllowOpenGLCanvas()) {
#ifdef USE_SKIA_GPU
    bool usingDynamicCache = gfxPrefs::CanvasSkiaGLDynamicCache();
    int cacheItemLimit = gfxPrefs::CanvasSkiaGLCacheItems();
    uint64_t cacheSizeLimit = std::max(gfxPrefs::CanvasSkiaGLCacheSize(), (int32_t)0);

    // Prefs are in megabytes, but we want the sizes in bytes
    cacheSizeLimit *= 1024*1024;

    if (usingDynamicCache) {
      if (mTotalSystemMemory < 512*1024*1024) {
        // We need a very minimal cache on anything smaller than 512mb.
        // Note the large jump as we cross 512mb (from 2mb to 32mb).
        cacheSizeLimit = 2*1024*1024;
      } else if (mTotalSystemMemory > 0) {
        cacheSizeLimit = mTotalSystemMemory / 16;
      }
    }

    // Ensure cache size doesn't overflow on 32-bit platforms.
    cacheSizeLimit = std::min(cacheSizeLimit, (uint64_t)SIZE_MAX);

  #ifdef DEBUG
    printf_stderr("Determined SkiaGL cache limits: Size %" PRIu64 ", Items: %i\n", cacheSizeLimit, cacheItemLimit);
  #endif

    mSkiaGlue->GetGrContext()->setResourceCacheLimits(cacheItemLimit, (size_t)cacheSizeLimit);
#endif
  }
}

SkiaGLGlue*
gfxPlatform::GetSkiaGLGlue()
{
#ifdef USE_SKIA_GPU
  // Check the accelerated Canvas is enabled for the first time,
  // because the callers should check it before using.
  if (!mSkiaGlue && !AllowOpenGLCanvas()) {
    return nullptr;
  }

  if (!mSkiaGlue) {
    /* Dummy context. We always draw into a FBO.
     *
     * FIXME: This should be stored in TLS or something, since there needs to be one for each thread using it. As it
     * stands, this only works on the main thread.
     */
    RefPtr<GLContext> glContext;
    nsCString discardFailureId;
    glContext = GLContextProvider::CreateHeadless(CreateContextFlags::REQUIRE_COMPAT_PROFILE |
                                                  CreateContextFlags::ALLOW_OFFLINE_RENDERER,
                                                  &discardFailureId);
    if (!glContext) {
      printf_stderr("Failed to create GLContext for SkiaGL!\n");
      return nullptr;
    }
    mSkiaGlue = new SkiaGLGlue(glContext);
    MOZ_ASSERT(mSkiaGlue->GetGrContext(), "No GrContext");
    InitializeSkiaCacheLimits();
  }
#endif

  return mSkiaGlue;
}

void
gfxPlatform::PurgeSkiaFontCache()
{
#ifdef USE_SKIA
  if (gfxPlatform::GetPlatform()->GetDefaultContentBackend() == BackendType::SKIA) {
    SkGraphics::PurgeFontCache();
  }
#endif
}

void
gfxPlatform::PurgeSkiaGPUCache()
{
#ifdef USE_SKIA_GPU
  if (!mSkiaGlue)
      return;

  mSkiaGlue->GetGrContext()->freeGpuResources();
  // GrContext::flush() doesn't call glFlush. Call it here.
  mSkiaGlue->GetGLContext()->MakeCurrent();
  mSkiaGlue->GetGLContext()->fFlush();
#endif
}

bool
gfxPlatform::HasEnoughTotalSystemMemoryForSkiaGL()
{
  return true;
}

already_AddRefed<DrawTarget>
gfxPlatform::CreateDrawTargetForBackend(BackendType aBackend, const IntSize& aSize, SurfaceFormat aFormat)
{
  // There is a bunch of knowledge in the gfxPlatform heirarchy about how to
  // create the best offscreen surface for the current system and situation. We
  // can easily take advantage of this for the Cairo backend, so that's what we
  // do.
  // mozilla::gfx::Factory can get away without having all this knowledge for
  // now, but this might need to change in the future (using
  // CreateOffscreenSurface() and CreateDrawTargetForSurface() for all
  // backends).
  if (aBackend == BackendType::CAIRO) {
    RefPtr<gfxASurface> surf = CreateOffscreenSurface(aSize, SurfaceFormatToImageFormat(aFormat));
    if (!surf || surf->CairoStatus()) {
      return nullptr;
    }
    return CreateDrawTargetForSurface(surf, aSize);
  }
  return Factory::CreateDrawTarget(aBackend, aSize, aFormat);
}

already_AddRefed<DrawTarget>
gfxPlatform::CreateOffscreenCanvasDrawTarget(const IntSize& aSize, SurfaceFormat aFormat)
{
  NS_ASSERTION(mPreferredCanvasBackend != BackendType::NONE, "No backend.");
  RefPtr<DrawTarget> target = CreateDrawTargetForBackend(mPreferredCanvasBackend, aSize, aFormat);
  if (target ||
      mFallbackCanvasBackend == BackendType::NONE) {
    return target.forget();
  }

#ifdef XP_WIN
  // On Windows, the fallback backend (Cairo) should use its image backend.
  return Factory::CreateDrawTarget(mFallbackCanvasBackend, aSize, aFormat);
#else
  return CreateDrawTargetForBackend(mFallbackCanvasBackend, aSize, aFormat);
#endif
}

already_AddRefed<DrawTarget>
gfxPlatform::CreateOffscreenContentDrawTarget(const IntSize& aSize,
                                              SurfaceFormat aFormat,
                                              bool aFallback)
{
  BackendType backend = (aFallback) ? mSoftwareBackend : mContentBackend;
  NS_ASSERTION(backend != BackendType::NONE, "No backend.");
  return CreateDrawTargetForBackend(backend, aSize, aFormat);
}

already_AddRefed<DrawTarget>
gfxPlatform::CreateSimilarSoftwareDrawTarget(DrawTarget* aDT,
                                             const IntSize& aSize,
                                             SurfaceFormat aFormat)
{
  RefPtr<DrawTarget> dt;

  if (Factory::DoesBackendSupportDataDrawtarget(aDT->GetBackendType())) {
    dt = aDT->CreateSimilarDrawTarget(aSize, aFormat);
  } else {
#ifdef USE_SKIA
    BackendType backendType = BackendType::SKIA;
#else
    BackendType backendType = BackendType::CAIRO;
#endif
    dt = Factory::CreateDrawTarget(backendType, aSize, aFormat);
  }

  return dt.forget();
}

/* static */ already_AddRefed<DrawTarget>
gfxPlatform::CreateDrawTargetForData(unsigned char* aData,
                                     const IntSize& aSize,
                                     int32_t aStride,
                                     SurfaceFormat aFormat,
                                     bool aUninitialized)
{
  BackendType backendType = gfxVars::ContentBackend();
  NS_ASSERTION(backendType != BackendType::NONE, "No backend.");

  if (!Factory::DoesBackendSupportDataDrawtarget(backendType)) {
#ifdef USE_SKIA
    backendType = BackendType::SKIA;
#else
    backendType = BackendType::CAIRO;
#endif
  }

  RefPtr<DrawTarget> dt = Factory::CreateDrawTargetForData(backendType,
                                                           aData, aSize,
                                                           aStride, aFormat,
                                                           aUninitialized);

  return dt.forget();
}

/* static */ BackendType
gfxPlatform::BackendTypeForName(const nsCString& aName)
{
  if (aName.EqualsLiteral("cairo"))
    return BackendType::CAIRO;
  if (aName.EqualsLiteral("skia"))
    return BackendType::SKIA;
  if (aName.EqualsLiteral("direct2d"))
    return BackendType::DIRECT2D;
  if (aName.EqualsLiteral("direct2d1.1"))
    return BackendType::DIRECT2D1_1;
  return BackendType::NONE;
}

nsresult
gfxPlatform::GetFontList(nsAtom *aLangGroup,
                         const nsACString& aGenericFamily,
                         nsTArray<nsString>& aListOfFonts)
{
    gfxPlatformFontList::PlatformFontList()->GetFontList(aLangGroup,
                                                         aGenericFamily,
                                                         aListOfFonts);
    return NS_OK;
}

nsresult
gfxPlatform::UpdateFontList()
{
    gfxPlatformFontList::PlatformFontList()->UpdateFontList();
    return NS_OK;
}

void
gfxPlatform::GetStandardFamilyName(const nsCString& aFontName,
                                   nsACString& aFamilyName)
{
    gfxPlatformFontList::PlatformFontList()->GetStandardFamilyName(aFontName,
                                                                   aFamilyName);
}

nsAutoCString
gfxPlatform::GetDefaultFontName(const nsACString& aLangGroup,
                                const nsACString& aGenericFamily)
{
    // To benefit from Return Value Optimization, all paths here must return
    // this one variable:
    nsAutoCString result;

    gfxFontFamily* fontFamily = gfxPlatformFontList::PlatformFontList()->
        GetDefaultFontFamily(aLangGroup, aGenericFamily);
    if (fontFamily) {
      fontFamily->LocalizedName(result);
    } // (else, leave 'result' empty)

    return result;
}

bool
gfxPlatform::DownloadableFontsEnabled()
{
    if (mAllowDownloadableFonts == UNINITIALIZED_VALUE) {
        mAllowDownloadableFonts =
            Preferences::GetBool(GFX_DOWNLOADABLE_FONTS_ENABLED, false);
    }

    return mAllowDownloadableFonts;
}

bool
gfxPlatform::UseCmapsDuringSystemFallback()
{
    if (mFallbackUsesCmaps == UNINITIALIZED_VALUE) {
        mFallbackUsesCmaps =
            Preferences::GetBool(GFX_PREF_FALLBACK_USE_CMAPS, false);
    }

    return mFallbackUsesCmaps;
}

bool
gfxPlatform::OpenTypeSVGEnabled()
{
    if (mOpenTypeSVGEnabled == UNINITIALIZED_VALUE) {
        mOpenTypeSVGEnabled =
            Preferences::GetBool(GFX_PREF_OPENTYPE_SVG, false);
    }

    return mOpenTypeSVGEnabled > 0;
}

uint32_t
gfxPlatform::WordCacheCharLimit()
{
    if (mWordCacheCharLimit == UNINITIALIZED_VALUE) {
        mWordCacheCharLimit =
            Preferences::GetInt(GFX_PREF_WORD_CACHE_CHARLIMIT, 32);
        if (mWordCacheCharLimit < 0) {
            mWordCacheCharLimit = 32;
        }
    }

    return uint32_t(mWordCacheCharLimit);
}

uint32_t
gfxPlatform::WordCacheMaxEntries()
{
    if (mWordCacheMaxEntries == UNINITIALIZED_VALUE) {
        mWordCacheMaxEntries =
            Preferences::GetInt(GFX_PREF_WORD_CACHE_MAXENTRIES, 10000);
        if (mWordCacheMaxEntries < 0) {
            mWordCacheMaxEntries = 10000;
        }
    }

    return uint32_t(mWordCacheMaxEntries);
}

bool
gfxPlatform::UseGraphiteShaping()
{
    if (mGraphiteShapingEnabled == UNINITIALIZED_VALUE) {
        mGraphiteShapingEnabled =
            Preferences::GetBool(GFX_PREF_GRAPHITE_SHAPING, false);
    }

    return mGraphiteShapingEnabled;
}

bool
gfxPlatform::IsFontFormatSupported(uint32_t aFormatFlags)
{
    // check for strange format flags
    MOZ_ASSERT(!(aFormatFlags & gfxUserFontSet::FLAG_FORMAT_NOT_USED),
               "strange font format hint set");

    // accept "common" formats that we support on all platforms
    if (aFormatFlags & gfxUserFontSet::FLAG_FORMATS_COMMON) {
        return true;
    }

    // reject all other formats, known and unknown
    if (aFormatFlags != 0) {
        return false;
    }

    // no format hint set, need to look at data
    return true;
}

gfxFontEntry*
gfxPlatform::LookupLocalFont(const nsACString& aFontName,
                             WeightRange aWeightForEntry,
                             StretchRange aStretchForEntry,
                             SlantStyleRange aStyleForEntry)
{
    return gfxPlatformFontList::PlatformFontList()->
        LookupLocalFont(aFontName, aWeightForEntry, aStretchForEntry,
                        aStyleForEntry);
}

gfxFontEntry*
gfxPlatform::MakePlatformFont(const nsACString& aFontName,
                              WeightRange aWeightForEntry,
                              StretchRange aStretchForEntry,
                              SlantStyleRange aStyleForEntry,
                              const uint8_t* aFontData,
                              uint32_t aLength)
{
    return gfxPlatformFontList::PlatformFontList()->
        MakePlatformFont(aFontName, aWeightForEntry, aStretchForEntry,
                         aStyleForEntry, aFontData, aLength);
}

mozilla::layers::DiagnosticTypes
gfxPlatform::GetLayerDiagnosticTypes()
{
  mozilla::layers::DiagnosticTypes type = DiagnosticTypes::NO_DIAGNOSTIC;
  if (gfxPrefs::DrawLayerBorders()) {
    type |= mozilla::layers::DiagnosticTypes::LAYER_BORDERS;
  }
  if (gfxPrefs::DrawTileBorders()) {
    type |= mozilla::layers::DiagnosticTypes::TILE_BORDERS;
  }
  if (gfxPrefs::DrawBigImageBorders()) {
    type |= mozilla::layers::DiagnosticTypes::BIGIMAGE_BORDERS;
  }
  if (gfxPrefs::FlashLayerBorders()) {
    type |= mozilla::layers::DiagnosticTypes::FLASH_BORDERS;
  }
  return type;
}

BackendPrefsData
gfxPlatform::GetBackendPrefs() const
{
  BackendPrefsData data;

  data.mCanvasBitmask = BackendTypeBit(BackendType::CAIRO);
  data.mContentBitmask = BackendTypeBit(BackendType::CAIRO);
#ifdef USE_SKIA
  data.mCanvasBitmask |= BackendTypeBit(BackendType::SKIA);
  data.mContentBitmask |= BackendTypeBit(BackendType::SKIA);
#endif
  data.mCanvasDefault = BackendType::CAIRO;
  data.mContentDefault = BackendType::CAIRO;

  return data;
}

void
gfxPlatform::InitBackendPrefs(BackendPrefsData&& aPrefsData)
{
    mPreferredCanvasBackend = GetCanvasBackendPref(aPrefsData.mCanvasBitmask);
    if (mPreferredCanvasBackend == BackendType::NONE) {
        mPreferredCanvasBackend = aPrefsData.mCanvasDefault;
    }

    if (mPreferredCanvasBackend == BackendType::DIRECT2D1_1) {
      // Falling back to D2D 1.0 won't help us here. When D2D 1.1 DT creation
      // fails it means the surface was too big or there's something wrong with
      // the device. D2D 1.0 will encounter a similar situation.
      mFallbackCanvasBackend =
          GetCanvasBackendPref(aPrefsData.mCanvasBitmask &
                               ~(BackendTypeBit(mPreferredCanvasBackend) | BackendTypeBit(BackendType::DIRECT2D)));
    } else {
      mFallbackCanvasBackend =
          GetCanvasBackendPref(aPrefsData.mCanvasBitmask & ~BackendTypeBit(mPreferredCanvasBackend));
    }


    mContentBackendBitmask = aPrefsData.mContentBitmask;
    mContentBackend = GetContentBackendPref(mContentBackendBitmask);
    if (mContentBackend == BackendType::NONE) {
        mContentBackend = aPrefsData.mContentDefault;
        // mContentBackendBitmask is our canonical reference for supported
        // backends so we need to add the default if we are using it and
        // overriding the prefs.
        mContentBackendBitmask |= BackendTypeBit(aPrefsData.mContentDefault);
    }

    uint32_t swBackendBits = BackendTypeBit(BackendType::SKIA) |
                             BackendTypeBit(BackendType::CAIRO);
    mSoftwareBackend = GetContentBackendPref(swBackendBits);

    if (XRE_IsParentProcess()) {
        gfxVars::SetContentBackend(mContentBackend);
        gfxVars::SetSoftwareBackend(mSoftwareBackend);
    }
}

/* static */ BackendType
gfxPlatform::GetCanvasBackendPref(uint32_t aBackendBitmask)
{
    return GetBackendPref("gfx.canvas.azure.backends", aBackendBitmask);
}

/* static */ BackendType
gfxPlatform::GetContentBackendPref(uint32_t &aBackendBitmask)
{
    return GetBackendPref("gfx.content.azure.backends", aBackendBitmask);
}

/* static */ BackendType
gfxPlatform::GetBackendPref(const char* aBackendPrefName, uint32_t &aBackendBitmask)
{
    nsTArray<nsCString> backendList;
    nsAutoCString prefString;
    if (NS_SUCCEEDED(Preferences::GetCString(aBackendPrefName, prefString))) {
        ParseString(prefString, ',', backendList);
    }

    uint32_t allowedBackends = 0;
    BackendType result = BackendType::NONE;
    for (uint32_t i = 0; i < backendList.Length(); ++i) {
        BackendType type = BackendTypeForName(backendList[i]);
        if (BackendTypeBit(type) & aBackendBitmask) {
            allowedBackends |= BackendTypeBit(type);
            if (result == BackendType::NONE) {
                result = type;
            }
        }
    }

    aBackendBitmask = allowedBackends;
    return result;
}

bool
gfxPlatform::InSafeMode()
{
  static bool sSafeModeInitialized = false;
  static bool sInSafeMode = false;

  if (!sSafeModeInitialized) {
    sSafeModeInitialized = true;
    nsCOMPtr<nsIXULRuntime> xr = do_GetService("@mozilla.org/xre/runtime;1");
    if (xr) {
      xr->GetInSafeMode(&sInSafeMode);
    }
  }
  return sInSafeMode;
}

bool
gfxPlatform::OffMainThreadCompositingEnabled()
{
  return UsesOffMainThreadCompositing();
}

eCMSMode
gfxPlatform::GetCMSMode()
{
    if (!gCMSInitialized) {
        int32_t mode = gfxPrefs::CMSMode();
        if (mode >= 0 && mode < eCMSMode_AllCount) {
            gCMSMode = static_cast<eCMSMode>(mode);
        }

        bool enableV4 = gfxPrefs::CMSEnableV4();
        if (enableV4) {
            qcms_enable_iccv4();
        }
        gCMSInitialized = true;
    }
    return gCMSMode;
}

int
gfxPlatform::GetRenderingIntent()
{
  // gfxPrefs.h is using 0 as the default for the rendering
  // intent preference, based on that being the value for
  // QCMS_INTENT_DEFAULT.  Assert here to catch if that ever
  // changes and we can then figure out what to do about it.
  MOZ_ASSERT(QCMS_INTENT_DEFAULT == 0);

  /* Try to query the pref system for a rendering intent. */
  int32_t pIntent = gfxPrefs::CMSRenderingIntent();
  if ((pIntent < QCMS_INTENT_MIN) || (pIntent > QCMS_INTENT_MAX)) {
    /* If the pref is out of range, use embedded profile. */
    pIntent = -1;
  }
  return pIntent;
}

void
gfxPlatform::TransformPixel(const Color& in, Color& out, qcms_transform *transform)
{

    if (transform) {
        /* we want the bytes in RGB order */
#ifdef IS_LITTLE_ENDIAN
        /* ABGR puts the bytes in |RGBA| order on little endian */
        uint32_t packed = in.ToABGR();
        qcms_transform_data(transform,
                       (uint8_t *)&packed, (uint8_t *)&packed,
                       1);
        out = Color::FromABGR(packed);
#else
        /* ARGB puts the bytes in |ARGB| order on big endian */
        uint32_t packed = in.UnusualToARGB();
        /* add one to move past the alpha byte */
        qcms_transform_data(transform,
                       (uint8_t *)&packed + 1, (uint8_t *)&packed + 1,
                       1);
        out = Color::UnusualFromARGB(packed);
#endif
    }

    else if (&out != &in)
        out = in;
}

void
gfxPlatform::GetPlatformCMSOutputProfile(void *&mem, size_t &size)
{
    mem = nullptr;
    size = 0;
}

void
gfxPlatform::GetCMSOutputProfileData(void *&mem, size_t &size)
{
    nsAutoCString fname;
    Preferences::GetCString("gfx.color_management.display_profile", fname);
    if (!fname.IsEmpty()) {
        qcms_data_from_path(fname.get(), &mem, &size);
    }
    else {
        gfxPlatform::GetPlatform()->GetPlatformCMSOutputProfile(mem, size);
    }
}

void
gfxPlatform::CreateCMSOutputProfile()
{
    if (!gCMSOutputProfile) {
        /* Determine if we're using the internal override to force sRGB as
           an output profile for reftests. See Bug 452125.

           Note that we don't normally (outside of tests) set a
           default value of this preference, which means nsIPrefBranch::GetBoolPref
           will typically throw (and leave its out-param untouched).
         */
        if (Preferences::GetBool(GFX_PREF_CMS_FORCE_SRGB, false)) {
            gCMSOutputProfile = GetCMSsRGBProfile();
        }

        if (!gCMSOutputProfile) {
            void* mem = nullptr;
            size_t size = 0;

            GetCMSOutputProfileData(mem, size);
            if ((mem != nullptr) && (size > 0)) {
                gCMSOutputProfile = qcms_profile_from_memory(mem, size);
                free(mem);
            }
        }

        /* Determine if the profile looks bogus. If so, close the profile
         * and use sRGB instead. See bug 460629, */
        if (gCMSOutputProfile && qcms_profile_is_bogus(gCMSOutputProfile)) {
            NS_ASSERTION(gCMSOutputProfile != GetCMSsRGBProfile(),
                         "Builtin sRGB profile tagged as bogus!!!");
            qcms_profile_release(gCMSOutputProfile);
            gCMSOutputProfile = nullptr;
        }

        if (!gCMSOutputProfile) {
            gCMSOutputProfile = GetCMSsRGBProfile();
        }
        /* Precache the LUT16 Interpolations for the output profile. See
           bug 444661 for details. */
        qcms_profile_precache_output_transform(gCMSOutputProfile);
    }
}

qcms_profile *
gfxPlatform::GetCMSOutputProfile()
{
    return gCMSOutputProfile;
}

qcms_profile *
gfxPlatform::GetCMSsRGBProfile()
{
    if (!gCMSsRGBProfile) {

        /* Create the profile using qcms. */
        gCMSsRGBProfile = qcms_profile_sRGB();
    }
    return gCMSsRGBProfile;
}

qcms_transform *
gfxPlatform::GetCMSRGBTransform()
{
    if (!gCMSRGBTransform && !gCMSRGBTransformFailed) {
        qcms_profile *inProfile, *outProfile;
        outProfile = GetCMSOutputProfile();
        inProfile = GetCMSsRGBProfile();

        if (!inProfile || !outProfile)
            return nullptr;

        gCMSRGBTransform = qcms_transform_create(inProfile, QCMS_DATA_RGB_8,
                                              outProfile, QCMS_DATA_RGB_8,
                                             QCMS_INTENT_PERCEPTUAL);
        if (!gCMSRGBTransform) {
            gCMSRGBTransformFailed = true;
        }
    }

    return gCMSRGBTransform;
}

qcms_transform *
gfxPlatform::GetCMSInverseRGBTransform()
{
    if (!gCMSInverseRGBTransform) {
        qcms_profile *inProfile, *outProfile;
        inProfile = GetCMSOutputProfile();
        outProfile = GetCMSsRGBProfile();

        if (!inProfile || !outProfile)
            return nullptr;

        gCMSInverseRGBTransform = qcms_transform_create(inProfile, QCMS_DATA_RGB_8,
                                                     outProfile, QCMS_DATA_RGB_8,
                                                     QCMS_INTENT_PERCEPTUAL);
    }

    return gCMSInverseRGBTransform;
}

qcms_transform *
gfxPlatform::GetCMSRGBATransform()
{
    if (!gCMSRGBATransform) {
        qcms_profile *inProfile, *outProfile;
        outProfile = GetCMSOutputProfile();
        inProfile = GetCMSsRGBProfile();

        if (!inProfile || !outProfile)
            return nullptr;

        gCMSRGBATransform = qcms_transform_create(inProfile, QCMS_DATA_RGBA_8,
                                               outProfile, QCMS_DATA_RGBA_8,
                                               QCMS_INTENT_PERCEPTUAL);
    }

    return gCMSRGBATransform;
}

/* Shuts down various transforms and profiles for CMS. */
static void ShutdownCMS()
{

    if (gCMSRGBTransform) {
        qcms_transform_release(gCMSRGBTransform);
        gCMSRGBTransform = nullptr;
    }
    if (gCMSInverseRGBTransform) {
        qcms_transform_release(gCMSInverseRGBTransform);
        gCMSInverseRGBTransform = nullptr;
    }
    if (gCMSRGBATransform) {
        qcms_transform_release(gCMSRGBATransform);
        gCMSRGBATransform = nullptr;
    }
    if (gCMSOutputProfile) {
        qcms_profile_release(gCMSOutputProfile);

        // handle the aliased case
        if (gCMSsRGBProfile == gCMSOutputProfile)
            gCMSsRGBProfile = nullptr;
        gCMSOutputProfile = nullptr;
    }
    if (gCMSsRGBProfile) {
        qcms_profile_release(gCMSsRGBProfile);
        gCMSsRGBProfile = nullptr;
    }

    // Reset the state variables
    gCMSMode = eCMSMode_Off;
    gCMSInitialized = false;
}

// default SetupClusterBoundaries, based on Unicode properties;
// platform subclasses may override if they wish
void
gfxPlatform::SetupClusterBoundaries(gfxTextRun *aTextRun, const char16_t *aString)
{
    if (aTextRun->GetFlags() & gfx::ShapedTextFlags::TEXT_IS_8BIT) {
        // 8-bit text doesn't have clusters.
        // XXX is this true in all languages???
        // behdad: don't think so.  Czech for example IIRC has a
        // 'ch' grapheme.
        // jfkthame: but that's not expected to behave as a grapheme cluster
        // for selection/editing/etc.
        return;
    }

    aTextRun->SetupClusterBoundaries(0, aString, aTextRun->GetLength());
}

int32_t
gfxPlatform::GetBidiNumeralOption()
{
    if (mBidiNumeralOption == UNINITIALIZED_VALUE) {
        mBidiNumeralOption = Preferences::GetInt(BIDI_NUMERAL_PREF, 0);
    }
    return mBidiNumeralOption;
}

/* static */ void
gfxPlatform::FlushFontAndWordCaches()
{
    gfxFontCache *fontCache = gfxFontCache::GetCache();
    if (fontCache) {
        fontCache->AgeAllGenerations();
        fontCache->FlushShapedWordCaches();
    }

    gfxPlatform::PurgeSkiaFontCache();
}

/* static */ void
gfxPlatform::ForceGlobalReflow()
{
    MOZ_ASSERT(NS_IsMainThread());
    if (XRE_IsParentProcess()) {
        // Modify a preference that will trigger reflow everywhere (in all
        // content processes, as well as the parent).
        static const char kPrefName[] = "font.internaluseonly.changed";
        bool fontInternalChange = Preferences::GetBool(kPrefName, false);
        Preferences::SetBool(kPrefName, !fontInternalChange);
    } else {
        // Send a notification that will be observed by PresShells in this
        // process only.
        nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
        if (obs) {
            obs->NotifyObservers(nullptr, "font-info-updated", nullptr);
        }
    }
}

void
gfxPlatform::FontsPrefsChanged(const char *aPref)
{
    NS_ASSERTION(aPref != nullptr, "null preference");
    if (!strcmp(GFX_DOWNLOADABLE_FONTS_ENABLED, aPref)) {
        mAllowDownloadableFonts = UNINITIALIZED_VALUE;
    } else if (!strcmp(GFX_PREF_FALLBACK_USE_CMAPS, aPref)) {
        mFallbackUsesCmaps = UNINITIALIZED_VALUE;
    } else if (!strcmp(GFX_PREF_WORD_CACHE_CHARLIMIT, aPref)) {
        mWordCacheCharLimit = UNINITIALIZED_VALUE;
        FlushFontAndWordCaches();
    } else if (!strcmp(GFX_PREF_WORD_CACHE_MAXENTRIES, aPref)) {
        mWordCacheMaxEntries = UNINITIALIZED_VALUE;
        FlushFontAndWordCaches();
    } else if (!strcmp(GFX_PREF_GRAPHITE_SHAPING, aPref)) {
        mGraphiteShapingEnabled = UNINITIALIZED_VALUE;
        FlushFontAndWordCaches();
    } else if (!strcmp(BIDI_NUMERAL_PREF, aPref)) {
        mBidiNumeralOption = UNINITIALIZED_VALUE;
    } else if (!strcmp(GFX_PREF_OPENTYPE_SVG, aPref)) {
        mOpenTypeSVGEnabled = UNINITIALIZED_VALUE;
        gfxFontCache::GetCache()->AgeAllGenerations();
        gfxFontCache::GetCache()->NotifyGlyphsChanged();
    }
}


mozilla::LogModule*
gfxPlatform::GetLog(eGfxLog aWhichLog)
{
    // logs shared across gfx
    static LazyLogModule sFontlistLog("fontlist");
    static LazyLogModule sFontInitLog("fontinit");
    static LazyLogModule sTextrunLog("textrun");
    static LazyLogModule sTextrunuiLog("textrunui");
    static LazyLogModule sCmapDataLog("cmapdata");
    static LazyLogModule sTextPerfLog("textperf");

    switch (aWhichLog) {
    case eGfxLog_fontlist:
        return sFontlistLog;
    case eGfxLog_fontinit:
        return sFontInitLog;
    case eGfxLog_textrun:
        return sTextrunLog;
    case eGfxLog_textrunui:
        return sTextrunuiLog;
    case eGfxLog_cmapdata:
        return sCmapDataLog;
    case eGfxLog_textperf:
        return sTextPerfLog;
    }

    MOZ_ASSERT_UNREACHABLE("Unexpected log type");
    return nullptr;
}

RefPtr<mozilla::gfx::DrawTarget>
gfxPlatform::ScreenReferenceDrawTarget()
{
  return (mScreenReferenceDrawTarget)
           ? mScreenReferenceDrawTarget
           : gPlatform->CreateOffscreenContentDrawTarget(
               IntSize(1, 1), SurfaceFormat::B8G8R8A8, true);
}

mozilla::gfx::SurfaceFormat
gfxPlatform::Optimal2DFormatForContent(gfxContentType aContent)
{
  switch (aContent) {
  case gfxContentType::COLOR:
    switch (GetOffscreenFormat()) {
    case SurfaceFormat::A8R8G8B8_UINT32:
      return mozilla::gfx::SurfaceFormat::B8G8R8A8;
    case SurfaceFormat::X8R8G8B8_UINT32:
      return mozilla::gfx::SurfaceFormat::B8G8R8X8;
    case SurfaceFormat::R5G6B5_UINT16:
      return mozilla::gfx::SurfaceFormat::R5G6B5_UINT16;
    default:
      MOZ_ASSERT_UNREACHABLE("unknown gfxImageFormat for "
                             "gfxContentType::COLOR");
      return mozilla::gfx::SurfaceFormat::B8G8R8A8;
    }
  case gfxContentType::ALPHA:
    return mozilla::gfx::SurfaceFormat::A8;
  case gfxContentType::COLOR_ALPHA:
    return mozilla::gfx::SurfaceFormat::B8G8R8A8;
  default:
    MOZ_ASSERT_UNREACHABLE("unknown gfxContentType");
    return mozilla::gfx::SurfaceFormat::B8G8R8A8;
  }
}

gfxImageFormat
gfxPlatform::OptimalFormatForContent(gfxContentType aContent)
{
  switch (aContent) {
  case gfxContentType::COLOR:
    return GetOffscreenFormat();
  case gfxContentType::ALPHA:
    return SurfaceFormat::A8;
  case gfxContentType::COLOR_ALPHA:
    return SurfaceFormat::A8R8G8B8_UINT32;
  default:
    MOZ_ASSERT_UNREACHABLE("unknown gfxContentType");
    return SurfaceFormat::A8R8G8B8_UINT32;
  }
}

/**
 * There are a number of layers acceleration (or layers in general) preferences
 * that should be consistent for the lifetime of the application (bug 840967).
 * As such, we will evaluate them all as soon as one of them is evaluated
 * and remember the values.  Changing these preferences during the run will
 * not have any effect until we restart.
 */
static mozilla::Atomic<bool> sLayersSupportsHardwareVideoDecoding(false);
static bool sLayersHardwareVideoDecodingFailed = false;
static bool sBufferRotationCheckPref = true;

static mozilla::Atomic<bool> sLayersAccelerationPrefsInitialized(false);

void VideoDecodingFailedChangedCallback(const char* aPref, void*)
{
  sLayersHardwareVideoDecodingFailed = Preferences::GetBool(aPref, false);
  gfxPlatform::GetPlatform()->UpdateCanUseHardwareVideoDecoding();
}

void
gfxPlatform::UpdateCanUseHardwareVideoDecoding()
{
  if (XRE_IsParentProcess()) {
    gfxVars::SetCanUseHardwareVideoDecoding(CanUseHardwareVideoDecoding());
  }
}

void
gfxPlatform::InitAcceleration()
{
  if (sLayersAccelerationPrefsInitialized) {
    return;
  }

  InitCompositorAccelerationPrefs();

  // If this is called for the first time on a non-main thread, we're screwed.
  // At the moment there's no explicit guarantee that the main thread calls
  // this before the compositor thread, but let's at least make the assumption
  // explicit.
  MOZ_ASSERT(NS_IsMainThread(), "can only initialize prefs on the main thread");

  gfxPrefs::GetSingleton();

  nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
  nsCString discardFailureId;
  int32_t status;

  if (XRE_IsParentProcess()) {
    gfxVars::SetBrowserTabsRemoteAutostart(BrowserTabsRemoteAutostart());
    gfxVars::SetOffscreenFormat(GetOffscreenFormat());
    gfxVars::SetRequiresAcceleratedGLContextForCompositorOGL(
              RequiresAcceleratedGLContextForCompositorOGL());
#ifdef XP_WIN
    if (NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_D3D11_KEYED_MUTEX,
                                               discardFailureId, &status))) {
      gfxVars::SetAllowD3D11KeyedMutex(status == nsIGfxInfo::FEATURE_STATUS_OK);
    } else {
      // If we couldn't properly evaluate the status, err on the side
      // of caution and give this functionality to the user.
      gfxCriticalNote << "Cannot evaluate keyed mutex feature status";
      gfxVars::SetAllowD3D11KeyedMutex(true);
    }
#endif
  }

  if (Preferences::GetBool("media.hardware-video-decoding.enabled", false) &&
#ifdef XP_WIN
      Preferences::GetBool("media.wmf.dxva.enabled", true) &&
#endif
      NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_HARDWARE_VIDEO_DECODING,
                                               discardFailureId, &status))) {
      if (status == nsIGfxInfo::FEATURE_STATUS_OK || gfxPrefs::HardwareVideoDecodingForceEnabled()) {
        sLayersSupportsHardwareVideoDecoding = true;
      }
  }

  sLayersAccelerationPrefsInitialized = true;

  if (XRE_IsParentProcess()) {
    Preferences::RegisterCallbackAndCall(VideoDecodingFailedChangedCallback,
                                         "media.hardware-video-decoding.failed");
    InitGPUProcessPrefs();
  }
}

void
gfxPlatform::InitGPUProcessPrefs()
{
  // We want to hide this from about:support, so only set a default if the
  // pref is known to be true.
  if (!gfxPrefs::GPUProcessEnabled() && !gfxPrefs::GPUProcessForceEnabled()) {
    return;
  }

  FeatureState& gpuProc = gfxConfig::GetFeature(Feature::GPU_PROCESS);

  // We require E10S - otherwise, there is very little benefit to the GPU
  // process, since the UI process must still use acceleration for
  // performance.
  if (!BrowserTabsRemoteAutostart()) {
    gpuProc.DisableByDefault(
      FeatureStatus::Unavailable,
      "Multi-process mode is not enabled",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_NO_E10S"));
  } else {
    gpuProc.SetDefaultFromPref(
      gfxPrefs::GetGPUProcessEnabledPrefName(),
      true,
      gfxPrefs::GetGPUProcessEnabledPrefDefault());
  }

  if (gfxPrefs::GPUProcessForceEnabled()) {
    gpuProc.UserForceEnable("User force-enabled via pref");
  }

  if (IsHeadless()) {
    gpuProc.ForceDisable(
      FeatureStatus::Blocked,
      "Headless mode is enabled",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_HEADLESS_MODE"));
    return;
  }
  if (InSafeMode()) {
    gpuProc.ForceDisable(
      FeatureStatus::Blocked,
      "Safe-mode is enabled",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_SAFE_MODE"));
    return;
  }
  if (gfxPrefs::LayerScopeEnabled()) {
    gpuProc.ForceDisable(
      FeatureStatus::Blocked,
      "LayerScope does not work in the GPU process",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_LAYERSCOPE"));
    return;
  }
}

void
gfxPlatform::InitCompositorAccelerationPrefs()
{
  const char *acceleratedEnv = PR_GetEnv("MOZ_ACCELERATED");

  FeatureState& feature = gfxConfig::GetFeature(Feature::HW_COMPOSITING);

  // Base value - does the platform allow acceleration?
  if (feature.SetDefault(AccelerateLayersByDefault(),
                         FeatureStatus::Blocked,
                         "Acceleration blocked by platform"))
  {
    if (gfxPrefs::LayersAccelerationDisabledDoNotUseDirectly()) {
      feature.UserDisable("Disabled by pref",
                          NS_LITERAL_CSTRING("FEATURE_FAILURE_COMP_PREF"));
    } else if (acceleratedEnv && *acceleratedEnv == '0') {
      feature.UserDisable("Disabled by envvar",
                          NS_LITERAL_CSTRING("FEATURE_FAILURE_COMP_ENV"));
    }
  } else {
    if (acceleratedEnv && *acceleratedEnv == '1') {
      feature.UserEnable("Enabled by envvar");
    }
  }

  // This has specific meaning elsewhere, so we always record it.
  if (gfxPrefs::LayersAccelerationForceEnabledDoNotUseDirectly()) {
    feature.UserForceEnable("Force-enabled by pref");
  }

  // Safe, headless, and record/replay modes override everything.
  if (InSafeMode()) {
    feature.ForceDisable(FeatureStatus::Blocked, "Acceleration blocked by safe-mode",
                         NS_LITERAL_CSTRING("FEATURE_FAILURE_COMP_SAFEMODE"));
  }
  if (IsHeadless()) {
    feature.ForceDisable(FeatureStatus::Blocked, "Acceleration blocked by headless mode",
                         NS_LITERAL_CSTRING("FEATURE_FAILURE_COMP_HEADLESSMODE"));
  }
  if (recordreplay::IsRecordingOrReplaying()) {
    feature.ForceDisable(FeatureStatus::Blocked, "Acceleration blocked by recording/replaying",
                         NS_LITERAL_CSTRING("FEATURE_FAILURE_COMP_RECORDREPLAY"));
  }
}

/*static*/ bool
gfxPlatform::WebRenderPrefEnabled()
{
  return gfxPrefs::WebRenderAll() || gfxPrefs::WebRenderEnabledDoNotUseDirectly();
}

/*static*/ bool
gfxPlatform::WebRenderEnvvarEnabled()
{
  const char* env = PR_GetEnv("MOZ_WEBRENDER");
  return (env && *env == '1');
}

/* This is a pretty conservative check for having a battery.
 * For now we'd rather err on the side of thinking we do. */
static bool HasBattery()
{
#ifdef XP_WIN
  SYSTEM_POWER_STATUS status;
  const BYTE NO_SYSTEM_BATTERY = 128;
  if (GetSystemPowerStatus(&status)) {
    if (status.BatteryFlag == NO_SYSTEM_BATTERY) {
      return false;
    }
  }
#endif
  return true;
}

void
gfxPlatform::InitWebRenderConfig()
{
  bool prefEnabled = WebRenderPrefEnabled();
  bool envvarEnabled = WebRenderEnvvarEnabled();

  // On Nightly:
  //   WR? WR+   => means WR was enabled via gfx.webrender.all.qualified
  //   WR! WR+   => means WR was enabled via gfx.webrender.{all,enabled} or envvar
  // On Beta/Release:
  //   WR? WR+   => means WR was enabled via gfx.webrender.all.qualified on qualified hardware
  //   WR! WR+   => means WR was enabled via envvar, possibly on unqualified hardware.
  // In all cases WR- means WR was not enabled, for one of many possible reasons.
  ScopedGfxFeatureReporter reporter("WR", prefEnabled || envvarEnabled);
  if (!XRE_IsParentProcess()) {
    // The parent process runs through all the real decision-making code
    // later in this function. For other processes we still want to report
    // the state of the feature for crash reports.
    if (gfxVars::UseWebRender()) {
      reporter.SetSuccessful();
    }
    return;
  }

  FeatureState& featureWebRenderQualified = gfxConfig::GetFeature(Feature::WEBRENDER_QUALIFIED);
  featureWebRenderQualified.EnableByDefault();
  nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
  nsCString failureId;
  int32_t status;
  if (NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_WEBRENDER,
                                             failureId, &status))) {
    if (status != nsIGfxInfo::FEATURE_STATUS_OK) {
      featureWebRenderQualified.Disable(FeatureStatus::Blocked,
                                         "No qualified hardware",
                                         failureId);
    } else if (HasBattery()) {
      featureWebRenderQualified.Disable(FeatureStatus::Blocked,
                                         "Has battery",
                                         NS_LITERAL_CSTRING("FEATURE_FAILURE_WR_HAS_BATTERY"));
    } else {
      nsAutoString adapterVendorID;
      gfxInfo->GetAdapterVendorID(adapterVendorID);
      if (adapterVendorID != u"0x10de") {
        featureWebRenderQualified.Disable(FeatureStatus::Blocked,
                                         "Not Nvidia",
                                         NS_LITERAL_CSTRING("FEATURE_FAILURE_NOT_NVIDIA"));
      } else {
        nsAutoString adapterDeviceID;
        gfxInfo->GetAdapterDeviceID(adapterDeviceID);
        nsresult valid;
        int32_t deviceID = adapterDeviceID.ToInteger(&valid, 16);
        if (valid != NS_OK) {
          featureWebRenderQualified.Disable(FeatureStatus::Blocked,
                                            "Bad device id",
                                            NS_LITERAL_CSTRING("FEATURE_FAILURE_BAD_DEVICE_ID"));
        } else if (deviceID < 0x6c0) {
           // 0x6c0 is the lowest Fermi device id. Unfortunately some Tesla devices that don't support D3D 10.1
           // have higher deviceIDs. They will be included, but blocked by ANGLE.
          featureWebRenderQualified.Disable(FeatureStatus::Blocked,
                                            "Device too old",
                                            NS_LITERAL_CSTRING("FEATURE_FAILURE_DEVICE_TOO_OLD"));
        }
      }
    }
  } else {
    featureWebRenderQualified.Disable(FeatureStatus::Blocked,
                                       "gfxInfo is broken",
                                       NS_LITERAL_CSTRING("FEATURE_FAILURE_WR_NO_GFX_INFO"));
  }

  FeatureState& featureWebRender = gfxConfig::GetFeature(Feature::WEBRENDER);

  featureWebRender.DisableByDefault(
      FeatureStatus::OptIn,
      "WebRender is an opt-in feature",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_DEFAULT_OFF"));

  // envvar works everywhere; we need this for testing in CI. Sadly this allows
  // beta/release to enable it on unqualified hardware, but at least this is
  // harder for the average person than flipping a pref.
  if (envvarEnabled) {
    featureWebRender.UserEnable("Force enabled by envvar");

  // gfx.webrender.enabled and gfx.webrender.all only work on nightly
#ifdef NIGHTLY_BUILD
  } else if (prefEnabled) {
    featureWebRender.UserEnable("Force enabled by pref");
#endif

  // gfx.webrender.all.qualified works on all channels
  } else if (gfxPrefs::WebRenderAllQualified()) {
    if (featureWebRenderQualified.IsEnabled()) {
      featureWebRender.UserEnable("Qualified enabled by pref ");
    } else {
      featureWebRender.ForceDisable(FeatureStatus::Blocked,
                                    "Qualified enable blocked",
                                    failureId);
    }
  }

  // If the user set the pref to force-disable, let's do that. This will
  // override all the other enabling prefs (gfx.webrender.enabled,
  // gfx.webrender.all, and gfx.webrender.all.qualified).
  if (gfxPrefs::WebRenderForceDisabled()) {
    featureWebRender.UserDisable(
      "User force-disabled WR",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_USER_FORCE_DISABLED"));
  }

  // HW_COMPOSITING being disabled implies interfacing with the GPU might break
  if (!gfxConfig::IsEnabled(Feature::HW_COMPOSITING)) {
    featureWebRender.ForceDisable(
      FeatureStatus::Unavailable,
      "Hardware compositing is disabled",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBRENDER_NEED_HWCOMP"));
  }

  // WebRender relies on the GPU process when on Windows
#ifdef XP_WIN
  if (!gfxConfig::IsEnabled(Feature::GPU_PROCESS)) {
    featureWebRender.ForceDisable(
      FeatureStatus::Unavailable,
      "GPU Process is disabled",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_GPU_PROCESS_DISABLED"));
  }
#endif

  if (InSafeMode()) {
    featureWebRender.ForceDisable(
      FeatureStatus::Unavailable,
      "Safe-mode is enabled",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_SAFE_MODE"));
  }

#ifndef MOZ_BUILD_WEBRENDER
  featureWebRender.ForceDisable(
    FeatureStatus::Unavailable,
    "Build doesn't include WebRender",
    NS_LITERAL_CSTRING("FEATURE_FAILURE_NO_WEBRENDER"));
#endif

#ifdef XP_WIN
  if (Preferences::GetBool("gfx.webrender.force-angle", false)) {
    if (!gfxConfig::IsEnabled(Feature::D3D11_HW_ANGLE)) {
      featureWebRender.ForceDisable(
        FeatureStatus::Unavailable,
        "ANGLE is disabled",
        NS_LITERAL_CSTRING("FEATURE_FAILURE_ANGLE_DISABLED"));
    } else {
      gfxVars::SetUseWebRenderANGLE(gfxConfig::IsEnabled(Feature::WEBRENDER));
    }
  }
#endif

  if (Preferences::GetBool("gfx.webrender.program-binary", false)) {
    gfxVars::SetUseWebRenderProgramBinary(gfxConfig::IsEnabled(Feature::WEBRENDER));
    if (Preferences::GetBool("gfx.webrender.program-binary-disk", false)) {
      gfxVars::SetUseWebRenderProgramBinaryDisk(gfxConfig::IsEnabled(Feature::WEBRENDER));
    }
  }

#ifdef MOZ_WIDGET_ANDROID
  featureWebRender.ForceDisable(
    FeatureStatus::Unavailable,
    "WebRender not ready for use on Android",
    NS_LITERAL_CSTRING("FEATURE_FAILURE_ANDROID"));
#endif

  // gfxFeature is not usable in the GPU process, so we use gfxVars to transmit this feature
  if (gfxConfig::IsEnabled(Feature::WEBRENDER)) {
    gfxVars::SetUseWebRender(true);
    reporter.SetSuccessful();

    if (XRE_IsParentProcess()) {
      Preferences::RegisterPrefixCallbackAndCall(WebRenderDebugPrefChangeCallback,
                                                 WR_DEBUG_PREF);
    }
  }

#ifdef XP_WIN
  if (Preferences::GetBool("gfx.webrender.dcomp-win.enabled", false)) {
    // XXX relax win version to windows 8.
    if (IsWin10OrLater() &&
        gfxVars::UseWebRender() &&
        gfxVars::UseWebRenderANGLE()) {
      gfxVars::SetUseWebRenderDCompWin(true);
    }
  }
#endif
}

void
gfxPlatform::InitOMTPConfig()
{
  ScopedGfxFeatureReporter reporter("OMTP");

  FeatureState& omtp = gfxConfig::GetFeature(Feature::OMTP);
  int32_t paintWorkerCount = PaintThread::CalculatePaintWorkerCount();

  if (!XRE_IsParentProcess()) {
    // The parent process runs through all the real decision-making code
    // later in this function. For other processes we still want to report
    // the state of the feature for crash reports.
    if (gfxVars::UseOMTP()) {
      reporter.SetSuccessful(paintWorkerCount);
    }
    return;
  }

  omtp.SetDefaultFromPref(
    "layers.omtp.enabled",
    true,
    Preferences::GetBool("layers.omtp.enabled", false, PrefValueKind::Default));

  if (mContentBackend == BackendType::CAIRO) {
    omtp.ForceDisable(FeatureStatus::Broken, "OMTP is not supported when using cairo",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_COMP_PREF"));
  }

#ifdef XP_MACOSX
  if (!nsCocoaFeatures::OnYosemiteOrLater()) {
    omtp.ForceDisable(FeatureStatus::Blocked, "OMTP blocked before OSX 10.10",
                      NS_LITERAL_CSTRING("FEATURE_FAILURE_OMTP_OSX_MAVERICKS"));
  }
#endif

  if (InSafeMode()) {
    omtp.ForceDisable(FeatureStatus::Blocked, "OMTP blocked by safe-mode",
                      NS_LITERAL_CSTRING("FEATURE_FAILURE_COMP_SAFEMODE"));
  }

  if (omtp.IsEnabled()) {
    gfxVars::SetUseOMTP(true);
    reporter.SetSuccessful(paintWorkerCount);
  }
}

bool
gfxPlatform::CanUseHardwareVideoDecoding()
{
  // this function is called from the compositor thread, so it is not
  // safe to init the prefs etc. from here.
  MOZ_ASSERT(sLayersAccelerationPrefsInitialized);
  return sLayersSupportsHardwareVideoDecoding && !sLayersHardwareVideoDecodingFailed;
}

bool
gfxPlatform::AccelerateLayersByDefault()
{
#if defined(MOZ_GL_PROVIDER) || defined(MOZ_WIDGET_UIKIT)
  return true;
#else
  return false;
#endif
}

bool
gfxPlatform::BufferRotationEnabled()
{
  MutexAutoLock autoLock(*gGfxPlatformPrefsLock);

  return sBufferRotationCheckPref && gfxPrefs::BufferRotationEnabled();
}

void
gfxPlatform::DisableBufferRotation()
{
  MutexAutoLock autoLock(*gGfxPlatformPrefsLock);

  sBufferRotationCheckPref = false;
}

/* static */ bool
gfxPlatform::UsesOffMainThreadCompositing()
{
  if (XRE_GetProcessType() == GeckoProcessType_GPU) {
    return true;
  }

  static bool firstTime = true;
  static bool result = false;

  if (firstTime) {
    MOZ_ASSERT(sLayersAccelerationPrefsInitialized);
    result =
      gfxVars::BrowserTabsRemoteAutostart() ||
      !gfxPrefs::LayersOffMainThreadCompositionForceDisabled();
#if defined(MOZ_WIDGET_GTK)
    // Linux users who chose OpenGL are being grandfathered in to OMTC
    result |= gfxPrefs::LayersAccelerationForceEnabledDoNotUseDirectly();

#endif
    firstTime = false;
  }

  return result;
}

bool
gfxPlatform::UsesTiling() const
{
  bool usesSkia = GetDefaultContentBackend() == BackendType::SKIA;

  // We can't just test whether the PaintThread is initialized here because
  // this function is used when initializing the PaintThread. So instead we
  // check the conditions that enable OMTP with parallel painting.
  bool usesPOMTP = XRE_IsContentProcess() &&
    gfxVars::UseOMTP() &&
    (gfxPrefs::LayersOMTPPaintWorkers() == -1 ||
      gfxPrefs::LayersOMTPPaintWorkers() > 1);

  return gfxPrefs::LayersTilesEnabled() ||
    (gfxPrefs::LayersTilesEnabledIfSkiaPOMTP() &&
      usesSkia &&
      usesPOMTP);
}

bool
gfxPlatform::ContentUsesTiling() const
{
  BackendPrefsData data = GetBackendPrefs();
  BackendType contentBackend = GetContentBackendPref(data.mContentBitmask);
  if (contentBackend == BackendType::NONE) {
    contentBackend = data.mContentDefault;
  }

  bool contentUsesSkia = contentBackend == BackendType::SKIA;
  bool contentUsesPOMTP = gfxVars::UseOMTP() &&
    (gfxPrefs::LayersOMTPPaintWorkers() == -1 ||
      gfxPrefs::LayersOMTPPaintWorkers() > 1);

  return gfxPrefs::LayersTilesEnabled() ||
    (gfxPrefs::LayersTilesEnabledIfSkiaPOMTP() &&
      contentUsesSkia &&
      contentUsesPOMTP);
}

/***
 * The preference "layout.frame_rate" has 3 meanings depending on the value:
 *
 * -1 = Auto (default), use hardware vsync or software vsync @ 60 hz if hw vsync fails.
 *  0 = ASAP mode - used during talos testing.
 *  X = Software vsync at a rate of X times per second.
 */
already_AddRefed<mozilla::gfx::VsyncSource>
gfxPlatform::CreateHardwareVsyncSource()
{
  RefPtr<mozilla::gfx::VsyncSource> softwareVsync = new SoftwareVsyncSource();
  return softwareVsync.forget();
}

/* static */ bool
gfxPlatform::IsInLayoutAsapMode()
{
  // There are 2 modes of ASAP mode.
  // 1 is that the refresh driver and compositor are in lock step
  // the second is that the compositor goes ASAP and the refresh driver
  // goes at whatever the configurated rate is. This only checks the version
  // talos uses, which is the refresh driver and compositor are in lockstep.
  return gfxPrefs::LayoutFrameRate() == 0;
}

/* static */ bool
gfxPlatform::ForceSoftwareVsync()
{
  return gfxPrefs::LayoutFrameRate() > 0 || recordreplay::IsRecordingOrReplaying();
}

/* static */ int
gfxPlatform::GetSoftwareVsyncRate()
{
  int preferenceRate = gfxPrefs::LayoutFrameRate();
  if (preferenceRate <= 0) {
    return gfxPlatform::GetDefaultFrameRate();
  }
  return preferenceRate;
}

/* static */ int
gfxPlatform::GetDefaultFrameRate()
{
  return 60;
}

void
gfxPlatform::GetAzureBackendInfo(mozilla::widget::InfoObject& aObj)
{
  if (gfxConfig::IsEnabled(Feature::GPU_PROCESS)) {
    aObj.DefineProperty("AzureCanvasBackend (UI Process)", GetBackendName(mPreferredCanvasBackend));
    aObj.DefineProperty("AzureFallbackCanvasBackend (UI Process)", GetBackendName(mFallbackCanvasBackend));
    aObj.DefineProperty("AzureContentBackend (UI Process)", GetBackendName(mContentBackend));

    // Assume content process' backend prefs.
    BackendPrefsData data = GetBackendPrefs();
    BackendType canvasBackend = GetCanvasBackendPref(data.mCanvasBitmask);
    if (canvasBackend == BackendType::NONE) {
      canvasBackend = data.mCanvasDefault;
    }
    BackendType contentBackend = GetContentBackendPref(data.mContentBitmask);
    if (contentBackend == BackendType::NONE) {
      contentBackend = data.mContentDefault;
    }
    aObj.DefineProperty("AzureCanvasBackend", GetBackendName(canvasBackend));
    aObj.DefineProperty("AzureContentBackend", GetBackendName(contentBackend));
  } else {
    aObj.DefineProperty("AzureCanvasBackend", GetBackendName(mPreferredCanvasBackend));
    aObj.DefineProperty("AzureFallbackCanvasBackend", GetBackendName(mFallbackCanvasBackend));
    aObj.DefineProperty("AzureContentBackend", GetBackendName(mContentBackend));
  }

  aObj.DefineProperty("AzureCanvasAccelerated", AllowOpenGLCanvas());
}

void
gfxPlatform::GetApzSupportInfo(mozilla::widget::InfoObject& aObj)
{
  if (!gfxPlatform::AsyncPanZoomEnabled()) {
    return;
  }

  if (SupportsApzWheelInput()) {
    aObj.DefineProperty("ApzWheelInput", 1);
  }

  if (SupportsApzTouchInput()) {
    aObj.DefineProperty("ApzTouchInput", 1);
  }

  if (SupportsApzDragInput()) {
    aObj.DefineProperty("ApzDragInput", 1);
  }

  if (SupportsApzKeyboardInput() && !gfxPrefs::AccessibilityBrowseWithCaret()) {
    aObj.DefineProperty("ApzKeyboardInput", 1);
  }

  if (SupportsApzAutoscrolling()) {
    aObj.DefineProperty("ApzAutoscrollInput", 1);
  }
}

void
gfxPlatform::GetTilesSupportInfo(mozilla::widget::InfoObject& aObj)
{
  if (!gfxPrefs::LayersTilesEnabled()) {
    return;
  }

  IntSize tileSize = gfxVars::TileSize();
  aObj.DefineProperty("TileHeight", tileSize.height);
  aObj.DefineProperty("TileWidth", tileSize.width);
}

/*static*/ bool
gfxPlatform::AsyncPanZoomEnabled()
{
#if !defined(MOZ_WIDGET_ANDROID) && !defined(MOZ_WIDGET_UIKIT)
  // For XUL applications (everything but Firefox on Android)
  // we only want to use APZ when E10S is enabled. If
  // we ever get input events off the main thread we can consider relaxing
  // this requirement.
  if (!BrowserTabsRemoteAutostart()) {
    return false;
  }
#endif
#ifdef MOZ_WIDGET_ANDROID
  return true;
#else
  if (!gfxPrefs::SingletonExists()) {
    // Make sure the gfxPrefs has been initialized before reading from it.
    MOZ_ASSERT(NS_IsMainThread());
    gfxPrefs::GetSingleton();
  }
  return gfxPrefs::AsyncPanZoomEnabledDoNotUseDirectly();
#endif
}

/*static*/ bool
gfxPlatform::PerfWarnings()
{
  return gfxPrefs::PerfWarnings();
}

void
gfxPlatform::GetAcceleratedCompositorBackends(nsTArray<LayersBackend>& aBackends)
{
  if (gfxConfig::IsEnabled(Feature::OPENGL_COMPOSITING)) {
    aBackends.AppendElement(LayersBackend::LAYERS_OPENGL);
  }
  else {
    static int tell_me_once = 0;
    if (!tell_me_once) {
      NS_WARNING("OpenGL-accelerated layers are not supported on this system");
      tell_me_once = 1;
    }
#ifdef MOZ_WIDGET_ANDROID
    MOZ_CRASH("OpenGL-accelerated layers are a hard requirement on this platform. "
              "Cannot continue without support for them");
#endif
  }
}

void
gfxPlatform::GetCompositorBackends(bool useAcceleration, nsTArray<mozilla::layers::LayersBackend>& aBackends)
{
  if (useAcceleration) {
    GetAcceleratedCompositorBackends(aBackends);
  }
  aBackends.AppendElement(LayersBackend::LAYERS_BASIC);
}

void
gfxPlatform::NotifyCompositorCreated(LayersBackend aBackend)
{
  if (mCompositorBackend == aBackend) {
    return;
  }

  if (mCompositorBackend != LayersBackend::LAYERS_NONE) {
    gfxCriticalNote << "Compositors might be mixed ("
      << int(mCompositorBackend) << "," << int(aBackend) << ")";
  }

  // Set the backend before we notify so it's available immediately.
  mCompositorBackend = aBackend;

  // Notify that we created a compositor, so telemetry can update.
  NS_DispatchToMainThread(
    NS_NewRunnableFunction("gfxPlatform::NotifyCompositorCreated", [] {
      if (nsCOMPtr<nsIObserverService> obsvc = services::GetObserverService()) {
        obsvc->NotifyObservers(nullptr, "compositor:created", nullptr);
      }
    }));
}

/* static */ void
gfxPlatform::NotifyGPUProcessDisabled()
{
  if (gfxConfig::IsEnabled(Feature::WEBRENDER)) {
    gfxConfig::GetFeature(Feature::WEBRENDER).ForceDisable(
      FeatureStatus::Unavailable,
      "GPU Process is disabled",
      NS_LITERAL_CSTRING("FEATURE_FAILURE_GPU_PROCESS_DISABLED"));
    gfxVars::SetUseWebRender(false);
  }
}

void
gfxPlatform::FetchAndImportContentDeviceData()
{
  MOZ_ASSERT(XRE_IsContentProcess());

  if (gContentDeviceInitData) {
    ImportContentDeviceData(*gContentDeviceInitData);
    return;
  }

  mozilla::dom::ContentChild* cc = mozilla::dom::ContentChild::GetSingleton();

  mozilla::gfx::ContentDeviceData data;
  cc->SendGetGraphicsDeviceInitData(&data);

  ImportContentDeviceData(data);
}

void
gfxPlatform::ImportContentDeviceData(const mozilla::gfx::ContentDeviceData& aData)
{
  MOZ_ASSERT(XRE_IsContentProcess());

  const DevicePrefs& prefs = aData.prefs();
  gfxConfig::Inherit(Feature::HW_COMPOSITING, prefs.hwCompositing());
  gfxConfig::Inherit(Feature::OPENGL_COMPOSITING, prefs.oglCompositing());
}

void
gfxPlatform::BuildContentDeviceData(mozilla::gfx::ContentDeviceData* aOut)
{
  MOZ_ASSERT(XRE_IsParentProcess());

  // Make sure our settings are synchronized from the GPU process.
  GPUProcessManager::Get()->EnsureGPUReady();

  aOut->prefs().hwCompositing() = gfxConfig::GetValue(Feature::HW_COMPOSITING);
  aOut->prefs().oglCompositing() = gfxConfig::GetValue(Feature::OPENGL_COMPOSITING);
}

void
gfxPlatform::ImportGPUDeviceData(const mozilla::gfx::GPUDeviceData& aData)
{
  MOZ_ASSERT(XRE_IsParentProcess());

  gfxConfig::ImportChange(Feature::OPENGL_COMPOSITING, aData.oglCompositing());
  gfxConfig::ImportChange(Feature::ADVANCED_LAYERS, aData.advancedLayers());
}

bool
gfxPlatform::SupportsApzTouchInput() const
{
  return dom::TouchEvent::PrefEnabled(nullptr);
}

bool
gfxPlatform::SupportsApzDragInput() const
{
  return gfxPrefs::APZDragEnabled();
}

bool
gfxPlatform::SupportsApzKeyboardInput() const
{
  return gfxPrefs::APZKeyboardEnabled();
}

bool
gfxPlatform::SupportsApzAutoscrolling() const
{
  return gfxPrefs::APZAutoscrollEnabled();
}

void
gfxPlatform::InitOpenGLConfig()
{
  #ifdef XP_WIN
  // Don't enable by default on Windows, since it could show up in about:support even
  // though it'll never get used. Only attempt if user enables the pref
  if (!Preferences::GetBool("layers.prefer-opengl")){
    return;
  }
  #endif

  FeatureState& openGLFeature = gfxConfig::GetFeature(Feature::OPENGL_COMPOSITING);

  // Check to see hw comp supported
  if (!gfxConfig::IsEnabled(Feature::HW_COMPOSITING)) {
    openGLFeature.DisableByDefault(FeatureStatus::Unavailable, "Hardware compositing is disabled",
                           NS_LITERAL_CSTRING("FEATURE_FAILURE_OPENGL_NEED_HWCOMP"));
    return;
  }

  #ifdef XP_WIN
  openGLFeature.SetDefaultFromPref(
    gfxPrefs::GetLayersPreferOpenGLPrefName(),
    true,
    gfxPrefs::GetLayersPreferOpenGLPrefDefault());
  #else
    openGLFeature.EnableByDefault();
  #endif

  // When layers acceleration is force-enabled, enable it even for blacklisted
  // devices.
  if (gfxPrefs::LayersAccelerationForceEnabledDoNotUseDirectly()) {
    openGLFeature.UserForceEnable("Force-enabled by pref");
    return;
  }

  nsCString message;
  nsCString failureId;
  if (!IsGfxInfoStatusOkay(nsIGfxInfo::FEATURE_OPENGL_LAYERS, &message, failureId)) {
    openGLFeature.Disable(FeatureStatus::Blacklisted, message.get(), failureId);
  }
}

bool
gfxPlatform::IsGfxInfoStatusOkay(int32_t aFeature, nsCString* aOutMessage, nsCString& aFailureId)
{
  nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
  if (!gfxInfo) {
    return true;
  }

  int32_t status;
  if (NS_SUCCEEDED(gfxInfo->GetFeatureStatus(aFeature, aFailureId, &status)) &&
      status != nsIGfxInfo::FEATURE_STATUS_OK)
  {
    aOutMessage->AssignLiteral("#BLOCKLIST_");
    aOutMessage->AppendASCII(aFailureId.get());
    return false;
  }

  return true;
}