Bug 1300121 - Flush the D3D11 immediate context if a composition is cancelled to avoid resources queing up in the driver. r=Bas

gfx/layers/Compositor.h

@@ -427,6 +427,8 @@ public:
    */
   virtual void EndFrame();
 
+  virtual void CancelFrame() { ReadUnlockTextures(); }
+
   virtual void SetDispAcquireFence(Layer* aLayer);
 
   /**

gfx/layers/composite/LayerManagerComposite.cpp

@@ -150,6 +150,7 @@ LayerManagerComposite::Destroy()
     if (mRoot) {
       RootLayer()->Destroy();
     }
+    mCompositor->CancelFrame();
     mRoot = nullptr;
     mClonedLayerTreeProperties = nullptr;
     mPaintCounter = nullptr;
@@ -1320,6 +1321,9 @@ LayerManagerComposite::AutoAddMaskEffect::~AutoAddMaskEffect()
 void
 LayerManagerComposite::ChangeCompositor(Compositor* aNewCompositor)
 {
+  if (mCompositor) {
+    mCompositor->CancelFrame();
+  }
   mCompositor = aNewCompositor;
   mTextRenderer = new TextRenderer(aNewCompositor);
   mTwoPassTmpTarget = nullptr;

gfx/layers/d3d11/CompositorD3D11.cpp

@@ -1031,6 +1031,7 @@ CompositorD3D11::BeginFrame(const nsIntRegion& aInvalidRegion,
   }
 
   if (clipRect.IsEmpty()) {
+    CancelFrame();
     *aRenderBoundsOut = IntRect();
     return;
   }
@@ -1184,6 +1185,15 @@ CompositorD3D11::EndFrame()
   mCurrentRT = nullptr;
 }
 
+void
+CompositorD3D11::CancelFrame()
+{
+  ReadUnlockTextures();
+  // Flush the context, otherwise the driver might hold some resources alive
+  // until the next flush or present.
+  mContext->Flush();
+}
+
 void
 CompositorD3D11::PrepareViewport(const gfx::IntSize& aSize)
 {

gfx/layers/d3d11/CompositorD3D11.h

@@ -115,6 +115,8 @@ public:
    */
   virtual void EndFrame() override;
 
+  virtual void CancelFrame() override;
+
   /**
    * Setup the viewport and projection matrix for rendering
    * to a window of the given dimensions.