cc: Add receiver for CompositorFrameAck in LayerTreeHostImpl and forward it to the renderer.

cc/layer_tree_host_impl.cc

Index: cc/layer_tree_host_impl.cc
diff --git a/cc/layer_tree_host_impl.cc b/cc/layer_tree_host_impl.cc
index 8f32526fbc635f0ef6ac3375c45755e1b89b4618..9983bbf2395ae2889ad808a96417c506ecc1980c 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -816,6 +816,17 @@ void LayerTreeHostImpl::onVSyncParametersChanged(double monotonicTimebase, doubl
     m_client->onVSyncParametersChanged(timebase, interval);
 }
 
+void LayerTreeHostImpl::onSendFrameToParentCompositorAck(const WebKit::WebCompositorFrameAck& webAck)
+{
+    if (!m_renderer)
+        return;
+
+    // TODO(piman): We may need to do some validation on this ack before processing it.
+    // TODO(danakj): This cast goes away when we move WebCompositorOutputSurface to cc::OutputSurface.
+    const CompositorFrameAck& ack = reinterpret_cast<const CompositorFrameAck&>(webAck);

[piman, 2012/12/06 18:07:05]

In the mean time, can we just make CompositorFrameAck derive from the (empty)
WebCompositorFrameAck and make this a static_cast ?

+    m_renderer->receiveCompositorFrameAck(ack);
+}
+
 void LayerTreeHostImpl::drawLayers(FrameData& frame)
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::drawLayers");