Backed out changeset f534fcb785c9 (bug 1167235)

dom/canvas/CanvasRenderingContext2D.cpp

@@ -745,36 +745,6 @@ NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(CanvasPattern, Release)
 
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(CanvasPattern, mContext)
 
-class CanvasShutdownObserver final : public nsIObserver
-{
-public:
-  explicit CanvasShutdownObserver(CanvasRenderingContext2D* aCanvas)
-  : mCanvas(aCanvas)
-  {}
-
-  NS_DECL_ISUPPORTS
-  NS_DECL_NSIOBSERVER
-private:
-  ~CanvasShutdownObserver() {}
-
-  CanvasRenderingContext2D* mCanvas;
-};
-
-NS_IMPL_ISUPPORTS(CanvasShutdownObserver, nsIObserver)
-
-NS_IMETHODIMP
-CanvasShutdownObserver::Observe(nsISupports *aSubject,
-                                const char *aTopic,
-                                const char16_t *aData)
-{
-  if (mCanvas && strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
-    mCanvas->OnShutdown();
-    nsContentUtils::UnregisterShutdownObserver(this);
-  }
-
-  return NS_OK;
-}
-
 class CanvasDrawObserver
 {
 public:
@@ -1074,9 +1044,6 @@ CanvasRenderingContext2D::CanvasRenderingContext2D()
 {
   sNumLivingContexts++;
 
-  mShutdownObserver = new CanvasShutdownObserver(this);
-  nsContentUtils::RegisterShutdownObserver(mShutdownObserver);
-
   // The default is to use OpenGL mode
   if (gfxPlatform::GetPlatform()->UseAcceleratedCanvas()) {
     mDrawObserver = new CanvasDrawObserver(this);
@@ -1089,7 +1056,6 @@ CanvasRenderingContext2D::~CanvasRenderingContext2D()
 {
   RemoveDrawObserver();
   RemovePostRefreshObserver();
-  RemoveShutdownObserver();
   Reset();
   // Drop references from all CanvasRenderingContext2DUserData to this context
   for (uint32_t i = 0; i < mUserDatas.Length(); ++i) {
@@ -1182,29 +1148,6 @@ CanvasRenderingContext2D::Reset()
   return NS_OK;
 }
 
-void
-CanvasRenderingContext2D::OnShutdown()
-{
-  mShutdownObserver = nullptr;
-
-  RefPtr<PersistentBufferProvider> provider = mBufferProvider;
-
-  Reset();
-
-  if (provider) {
-    provider->OnShutdown();
-  }
-}
-
-void
-CanvasRenderingContext2D::RemoveShutdownObserver()
-{
-  if (mShutdownObserver) {
-    nsContentUtils::UnregisterShutdownObserver(mShutdownObserver);
-    mShutdownObserver = nullptr;
-  }
-}
-
 void
 CanvasRenderingContext2D::SetStyleFromString(const nsAString& aStr,
                                              Style aWhichStyle)
@@ -1513,13 +1456,6 @@ CanvasRenderingContext2D::RenderingMode
 CanvasRenderingContext2D::EnsureTarget(const gfx::Rect* aCoveredRect,
                                        RenderingMode aRenderingMode)
 {
-  if (AlreadyShutDown()) {
-    gfxCriticalError() << "Attempt to render into a Canvas2d after shutdown.";
-    EnsureErrorTarget();
-    mTarget = sErrorTarget;
-    return aRenderingMode;
-  }
-
   // This would make no sense, so make sure we don't get ourselves in a mess
   MOZ_ASSERT(mRenderingMode != RenderingMode::DefaultBackendMode);
 
@@ -5755,10 +5691,6 @@ void CanvasRenderingContext2D::RemoveDrawObserver()
 PersistentBufferProvider*
 CanvasRenderingContext2D::GetBufferProvider(LayerManager* aManager)
 {
-  if (AlreadyShutDown()) {
-    return nullptr;
-  }
-
   if (mBufferProvider) {
     return mBufferProvider;
   }

dom/canvas/CanvasRenderingContext2D.h

@@ -54,7 +54,6 @@ template<typename T> class Optional;
 struct CanvasBidiProcessor;
 class CanvasRenderingContext2DUserData;
 class CanvasDrawObserver;
-class CanvasShutdownObserver;
 
 /**
  ** CanvasRenderingContext2D
@@ -546,7 +545,6 @@ public:
   // return true and fills in the bound rect if element has a hit region.
   bool GetHitRegionRect(Element* aElement, nsRect& aRect) override;
 
-  void OnShutdown();
 protected:
   nsresult GetImageDataArray(JSContext* aCx, int32_t aX, int32_t aY,
                              uint32_t aWidth, uint32_t aHeight,
@@ -751,10 +749,6 @@ protected:
   CanvasDrawObserver* mDrawObserver;
   void RemoveDrawObserver();
 
-  RefPtr<CanvasShutdownObserver> mShutdownObserver;
-  void RemoveShutdownObserver();
-  bool AlreadyShutDown() const { return !mShutdownObserver; }
-
   /**
     * Flag to avoid duplicate calls to InvalidateFrame. Set to true whenever
     * Redraw is called, reset to false when Render is called.

dom/html/HTMLCanvasElement.cpp

@@ -353,7 +353,8 @@ HTMLCanvasElement::HTMLCanvasElement(already_AddRefed<mozilla::dom::NodeInfo>& a
   : nsGenericHTMLElement(aNodeInfo),
     mResetLayer(true) ,
     mWriteOnly(false)
-{}
+{
+}
 
 HTMLCanvasElement::~HTMLCanvasElement()
 {

gfx/layers/PersistentBufferProvider.cpp

@@ -126,7 +126,16 @@ PersistentBufferProviderShared::~PersistentBufferProviderShared()
     mFwd->GetActiveResourceTracker().RemoveObject(this);
   }
 
-  Destroy();
+  mDrawTarget = nullptr;
+  if (mBack && mBack->IsLocked()) {
+    mBack->Unlock();
+  }
+  if (mFront && mFront->IsLocked()) {
+    mFront->Unlock();
+  }
+  if (mBuffer && mBuffer->IsLocked()) {
+    mBuffer->Unlock();
+  }
 }
 
 already_AddRefed<gfx::DrawTarget>
@@ -267,28 +276,5 @@ PersistentBufferProviderShared::NotifyInactive()
   mBuffer = nullptr;
 }
 
-void
-PersistentBufferProviderShared::Destroy()
-{
-  mSnapshot = nullptr;
-  mDrawTarget = nullptr;
-
-  if (mFront && mFront->IsLocked()) {
-    mFront->Unlock();
-  }
-
-  if (mBack && mBack->IsLocked()) {
-    mBack->Unlock();
-  }
-
-  if (mBuffer && mBuffer->IsLocked()) {
-    mBuffer->Unlock();
-  }
-
-  mFront = nullptr;
-  mBack = nullptr;
-  mBuffer = nullptr;
-}
-
 } // namespace layers
 } // namespace mozilla

gfx/layers/PersistentBufferProvider.h

@@ -60,8 +60,6 @@ public:
   virtual void ReturnSnapshot(already_AddRefed<gfx::SourceSurface> aSnapshot) = 0;
 
   virtual TextureClient* GetTextureClient() { return nullptr; }
-
-  virtual void OnShutdown() {}
 };
 
 
@@ -123,8 +121,6 @@ public:
 
   virtual void NotifyInactive() override;
 
-  virtual void OnShutdown() override { Destroy(); }
-
 protected:
   PersistentBufferProviderShared(gfx::IntSize aSize, gfx::SurfaceFormat aFormat,
                                  CompositableForwarder* aFwd,
@@ -132,8 +128,6 @@ protected:
 
   ~PersistentBufferProviderShared();
 
-  void Destroy();
-
   gfx::IntSize mSize;
   gfx::SurfaceFormat mFormat;
   RefPtr<CompositableForwarder> mFwd;

gfx/layers/client/TextureClient.cpp

@@ -364,8 +364,6 @@ void TextureClient::Destroy(bool aForceSync)
     mActor->Lock();
   }
 
-  mReadLock = nullptr;
-
   CancelWaitFenceHandleOnImageBridge();
   RefPtr<TextureChild> actor = mActor;
   mActor = nullptr;