Add layer name into frame viewer

cc/layers/heads_up_display_layer.cc

 // Copyright 2012 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 "cc/layers/heads_up_display_layer.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "cc/layers/heads_up_display_layer_impl.h"
@@ skipping 37 matching lines @@
 }
 
 bool HeadsUpDisplayLayer::DrawsContent() const { return true; }
 
 scoped_ptr<LayerImpl> HeadsUpDisplayLayer::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
   return HeadsUpDisplayLayerImpl::Create(tree_impl, layer_id_).
       PassAs<LayerImpl>();
 }
 
+std::string HeadsUpDisplayLayer::DebugName() {
+  return std::string("Heads Up Display Layer");
+}
+
 }  // namespace cc