Bug 801176 - part7-v1: Don't remove TextureClient until the frame update is done. r=roc

---
 gfx/layers/client/CanvasClient.cpp | 10 ++++++++--
 gfx/layers/client/CanvasClient.h   |  2 ++
 2 files changed, 10 insertions(+), 2 deletions(-)

gfx/layers/client/CanvasClient.cpp

@@ -87,7 +87,6 @@ CanvasClient2D::UpdateAsync(AsyncCanvasRenderer* aRenderer)
 void
 CanvasClient2D::UpdateRenderer(gfx::IntSize aSize, Renderer& aRenderer)
 {
-  AutoRemoveTexture autoRemove(this);
   ClientCanvasLayer* layer = nullptr;
   AsyncCanvasRenderer* asyncRenderer = nullptr;
   if (aRenderer.constructed<ClientCanvasLayer*>()) {
@@ -98,7 +97,7 @@ CanvasClient2D::UpdateRenderer(gfx::IntSize aSize, Renderer& aRenderer)
 
   if (mBuffer &&
       (mBuffer->IsImmutable() || mBuffer->GetSize() != aSize)) {
-    autoRemove.mTexture = mBuffer;
+    mPrevBuffer = mBuffer;
     mBuffer = nullptr;
   }
 
@@ -155,6 +154,13 @@ CanvasClient2D::UpdateRenderer(gfx::IntSize aSize, Renderer& aRenderer)
 void
 CanvasClient2D::Updated()
 {
+  AutoRemoveTexture autoRemove(this);
+
+  if (mPrevBuffer) {
+    autoRemove.mTexture = mPrevBuffer;
+    mPrevBuffer = nullptr;
+  }
+
   if (mBufferCreated && !AddTextureClient(mBuffer)) {
     mBuffer = nullptr;
     return;

gfx/layers/client/CanvasClient.h

@@ -89,6 +89,7 @@ public:
   CanvasClient2D(CompositableForwarder* aLayerForwarder,
                  TextureFlags aFlags)
     : CanvasClient(aLayerForwarder, aFlags),
+      mPrevBuffer(nullptr),
       mBufferCreated(false),
       mUpdated(false)
   {
@@ -128,6 +129,7 @@ private:
                                  TextureFlags aFlags,
                                  ClientCanvasLayer* aLayer);
 
+  RefPtr<TextureClient> mPrevBuffer;
   RefPtr<TextureClient> mBuffer;
   bool mBufferCreated;
   bool mUpdated;