Bug 1337487 - Disable WebRender on windows when the GPU process is disabled r=kats

--HG--
extra : amend_source : 0203452b319c21331f1f0ebcd74e3f843b7785e1

gfx/config/gfxFeature.h

@@ -25,6 +25,7 @@ namespace gfx {
   _(D3D11_HW_ANGLE,               Feature,      "Direct3D11 hardware ANGLE")      \
   _(DIRECT_DRAW,                  Feature,      "DirectDraw")                     \
   _(GPU_PROCESS,                  Feature,      "GPU Process")                    \
+  _(WEBRENDER,                    Feature,      "WebRender")                      \
   /* Add new entries above this comment */
 
 enum class Feature : uint32_t {

gfx/ipc/GPUProcessManager.cpp

@@ -154,6 +154,8 @@ GPUProcessManager::DisableGPUProcess(const char* aMessage)
   gfxConfig::SetFailed(Feature::GPU_PROCESS, FeatureStatus::Failed, aMessage);
   gfxCriticalNote << aMessage;
 
+  gfxPlatform::NotifyGPUProcessDisabled();
+
   DestroyProcess();
   ShutdownVsyncIOThread();
 }

gfx/thebes/gfxPlatform.cpp

@@ -689,18 +689,6 @@ gfxPlatform::Init()
 #endif
     gPlatform->InitAcceleration();
 
-#ifdef MOZ_ENABLE_WEBRENDER
-    if (XRE_IsParentProcess()) {
-      // XXX: right now this is just based on the pref. But we may want to
-      // do other runtime detection of hardware support etc.
-      // This pref defaults to true, so builds with --enable-webrender have it
-      // turned on by default, but can have it disabled via pref. The ifdef
-      // guards this entire block, so builds without --enable-webrender will
-      // always have the gfxVar default to false.
-      gfxVars::SetUseWebRender(Preferences::GetBool("gfx.webrender.enabled", true));
-    }
-#endif
-
     if (gfxConfig::IsEnabled(Feature::GPU_PROCESS)) {
       GPUProcessManager* gpu = GPUProcessManager::Get();
       gpu->LaunchGPUProcess();
@@ -2225,6 +2213,7 @@ gfxPlatform::InitAcceleration()
                                          nullptr,
                                          Preferences::ExactMatch);
     InitGPUProcessPrefs();
+    InitWebRenderConfig();
   }
 }
 
@@ -2311,6 +2300,47 @@ gfxPlatform::InitCompositorAccelerationPrefs()
   }
 }
 
+void
+gfxPlatform::InitWebRenderConfig()
+{
+  FeatureState& featureWebRender = gfxConfig::GetFeature(Feature::WEBRENDER);
+
+  featureWebRender.EnableByDefault();
+
+  if (!Preferences::GetBool("gfx.webrender.enabled", false)) {
+    featureWebRender.UserDisable(
+      "User disabled WebRender",
+      NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBRENDER_DISABLED"));
+  }
+
+  // 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_ENABLE_WEBRENDER
+  featureWebRender.ForceDisable(
+    FeatureStatus::Unavailable,
+    "Build doesn't include WebRender",
+    NS_LITERAL_CSTRING("FEATURE_FAILURE_NO_WEBRENDER"));
+#endif
+
+  // gfxFeature is not usable in the GPU process, so we use gfxVars to transmit this feature
+  gfxVars::SetUseWebRender(gfxConfig::IsEnabled(Feature::WEBRENDER));
+}
+
 bool
 gfxPlatform::CanUseHardwareVideoDecoding()
 {
@@ -2561,6 +2591,18 @@ gfxPlatform::NotifyCompositorCreated(LayersBackend aBackend)
   }));
 }
 
+/* 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()
 {

gfx/thebes/gfxPlatform.h

@@ -652,6 +652,8 @@ public:
      */
     static bool PerfWarnings();
 
+    static void NotifyGPUProcessDisabled();
+
     void NotifyCompositorCreated(mozilla::layers::LayersBackend aBackend);
     mozilla::layers::LayersBackend GetCompositorBackend() const {
       return mCompositorBackend;
@@ -820,6 +822,7 @@ private:
 
     void InitCompositorAccelerationPrefs();
     void InitGPUProcessPrefs();
+    void InitWebRenderConfig();
 
     static bool IsDXInterop2Blocked();
 

modules/libpref/init/all.js

@@ -810,9 +810,7 @@ pref("gfx.logging.peak-texture-usage.enabled", false);
 
 pref("gfx.ycbcr.accurate-conversion", false);
 
-#ifdef MOZ_ENABLE_WEBRENDER
 pref("gfx.webrender.enabled", true);
-#endif
 
 pref("accessibility.browsewithcaret", false);
 pref("accessibility.warn_on_browsewithcaret", true);