Add LayerTreeHostClient::{will,did}UpdateLayer, report layer updates to DevTools

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 341 matching lines @@
 
 void RenderWidgetCompositor::SetNeedsRedrawRect(gfx::Rect damage_rect) {
   layer_tree_host_->SetNeedsRedrawRect(damage_rect);
 }
 
 void RenderWidgetCompositor::SetLatencyInfo(
     const ui::LatencyInfo& latency_info) {
   layer_tree_host_->SetLatencyInfo(latency_info);
 }
 
+int RenderWidgetCompositor::GetLayerTreeId() const {
+  return layer_tree_host_->id();
+}
+
 bool RenderWidgetCompositor::initialize(cc::LayerTreeSettings settings) {
   scoped_refptr<base::MessageLoopProxy> compositor_message_loop_proxy =
       RenderThreadImpl::current()->compositor_message_loop_proxy();
   layer_tree_host_ = cc::LayerTreeHost::Create(this,
                                                settings,
                                                compositor_message_loop_proxy);
   return layer_tree_host_;
 }
 
 void RenderWidgetCompositor::setSurfaceReady() {
@@ skipping 197 matching lines @@
   return RenderThreadImpl::current()->OffscreenContextProviderForMainThread();
 }
 
 scoped_refptr<cc::ContextProvider>
 RenderWidgetCompositor::OffscreenContextProviderForCompositorThread() {
   return RenderThreadImpl::current()->
       OffscreenContextProviderForCompositorThread();
 }
 
 }  // namespace content