Propagate source_frame_number from LTH to DevTools

cc/trees/layer_tree_host.h

 // Copyright 2011 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.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <limits>
 #include <list>
 #include <string>
@@ skipping 84 matching lines @@
   virtual ~LayerTreeHost();
 
   void SetLayerTreeHostClientReady();
 
   void set_needs_filter_context() { needs_filter_context_ = true; }
   bool needs_offscreen_context() const {
     return needs_filter_context_;
   }
 
   // LayerTreeHost interface to Proxy.
-  void WillBeginMainFrame() { client_->WillBeginMainFrame(); }
+  void WillBeginMainFrame() {
+    client_->WillBeginMainFrame(source_frame_number_);
+  }
   void DidBeginMainFrame();
   void UpdateClientAnimations(base::TimeTicks monotonic_frame_begin_time);
   void AnimateLayers(base::TimeTicks monotonic_frame_begin_time);
   void DidStopFlinging();
   void Layout();
   void BeginCommitOnImplThread(LayerTreeHostImpl* host_impl);
   void FinishCommitOnImplThread(LayerTreeHostImpl* host_impl);
   void WillCommit();
   void CommitComplete();
   scoped_ptr<OutputSurface> CreateOutputSurface();
@@ skipping 314 matching lines @@
   scoped_refptr<Layer> outer_viewport_scroll_layer_;
 
   SharedBitmapManager* shared_bitmap_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_