Aura: Have ui::Layer implement WebKit::WebExternalTextureLayerClient

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index 148a5bd28c782ebc0a5ebac6fa65742d4d092717..4eaf4c663a89e9942e90062f9f7fe33e4a7fa8f3 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -162,6 +162,9 @@ Compositor::Compositor(CompositorDelegate* delegate,
 }
 
 Compositor::~Compositor() {
+  // Clear out any pending callbacks.
+  didCommit();

[piman, 2012/07/12 17:42:27]

Is this still needed? I figure by the time we get here, the RWHVA will have been
removed from the tree and so they will do whatever is necessary to execute their
callbacks before then.
I guess my main question is what makes didCommit special as opposed to all the
other ones in CompositorObserver.

[jonathan.backer, 2012/07/13 13:26:24]

You're right. There's nothing special. We'll leave it up to the
CompositorObserver. I checked with breakpoints and we're covered.

Done.

+
   // Don't call |CompositorDelegate::ScheduleDraw| from this point.
   delegate_ = NULL;
   // There's a cycle between |root_web_layer_| and |host_|, which results in
@@ -170,6 +173,11 @@ Compositor::~Compositor() {
   host_.setRootLayer(NULL);
   if (root_layer_)
     root_layer_->SetCompositor(NULL);
+
+  // Stop all outstanding draws before telling the ContextFactory to tear
+  // down any contexts that the |host_| may rely upon.
+  host_.reset();
+
   if (!test_compositor_enabled)
     ContextFactory::GetInstance()->RemoveCompositor(this);
 }
@@ -292,6 +300,10 @@ bool Compositor::HasObserver(CompositorObserver* observer) {
   return observer_list_.HasObserver(observer);
 }
 
+bool Compositor::IsThreaded() const {
+  return g_compositor_thread != NULL;
+}
+
 void Compositor::OnSwapBuffersPosted() {
   swap_posted_ = true;
 }
@@ -342,6 +354,14 @@ WebKit::WebGraphicsContext3D* Compositor::createContext3D() {
 void Compositor::didRebindGraphicsContext(bool success) {
 }
 
+// Called once per draw in single-threaded compositor mode and potentially
+// many times between draws in the multi-threaded compositor mode.
+void Compositor::didCommit() {
+  FOR_EACH_OBSERVER(CompositorObserver,
+                    observer_list_,
+                    OnCompositingDidCommit(this));
+}
+
 void Compositor::didCommitAndDrawFrame() {
   // TODO(backer): Plumb through an earlier impl side will start.
   if (g_compositor_thread)