Bug 1290081 - Make canvas layer transactions asynchronous. r=sotaro

gfx/layers/client/CanvasClient.cpp

@@ -98,8 +98,7 @@ CanvasClient2D::Update(gfx::IntSize aSize, ClientCanvasLayer* aLayer)
   mBufferProviderTexture = nullptr;
 
   AutoRemoveTexture autoRemove(this);
-  if (mBackBuffer &&
+  if (mBackBuffer && (mBackBuffer->IsReadLocked() || mBackBuffer->GetSize() != aSize)) {
-      (mBackBuffer->IsImmutable() || mBackBuffer->GetSize() != aSize)) {
     autoRemove.mTexture = mBackBuffer;
     mBackBuffer = nullptr;
   }
@@ -122,6 +121,7 @@ CanvasClient2D::Update(gfx::IntSize aSize, ClientCanvasLayer* aLayer)
       NS_WARNING("Failed to allocate the TextureClient");
       return;
     }
+    mBackBuffer->EnableReadLock();
     MOZ_ASSERT(mBackBuffer->CanExposeDrawTarget());
 
     bufferCreated = true;

gfx/layers/client/ClientCanvasLayer.cpp

@@ -90,16 +90,11 @@ ClientCanvasLayer::RenderLayer()
   RenderMaskLayers(this);
 
   if (!mCanvasClient) {
-    TextureFlags flags = TextureFlags::IMMEDIATE_UPLOAD;
+    TextureFlags flags = TextureFlags::DEFAULT;
     if (mOriginPos == gl::OriginPos::BottomLeft) {
       flags |= TextureFlags::ORIGIN_BOTTOM_LEFT;
     }
 
-    if (!mGLContext) {
-      // We don't support locking for buffer surfaces currently
-      flags |= TextureFlags::IMMEDIATE_UPLOAD;
-    }
-
     if (!mIsAlphaPremultiplied) {
       flags |= TextureFlags::NON_PREMULTIPLIED;
     }