Record layer name when recording paint event.

ui/compositor/layer.cc

 // Copyright (c) 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 "ui/compositor/layer.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 711 matching lines @@
   delegate_->OnDelegatedFrameDamage(damage_rect_in_dip);
 }
 
 void Layer::RequestCopyOfOutput(scoped_ptr<cc::CopyOutputRequest> request) {
   cc_layer_->RequestCopyOfOutput(request.Pass());
 }
 
 void Layer::PaintContents(SkCanvas* sk_canvas,
                           const gfx::Rect& clip,
                           ContentLayerClient::GraphicsContextStatus gc_status) {
-  TRACE_EVENT0("ui", "Layer::PaintContents");
+  TRACE_EVENT1("ui", "Layer::PaintContents", "name", name_);
   scoped_ptr<gfx::Canvas> canvas(gfx::Canvas::CreateCanvasWithoutScaling(
       sk_canvas, device_scale_factor_));
   if (delegate_)
     delegate_->OnPaintLayer(canvas.get());
 }
 
 scoped_refptr<cc::DisplayItemList> Layer::PaintContentsToDisplayList(
     const gfx::Rect& clip,
     ContentLayerClient::GraphicsContextStatus gc_status) {
   NOTIMPLEMENTED();
@@ skipping 323 matching lines @@
       children_.end(),
       std::bind2nd(std::mem_fun(&Layer::RemoveAnimatorsInTreeFromCollection),
                    collection));
 }
 
 bool Layer::IsAnimating() const {
   return animator_.get() && animator_->is_animating();
 }
 
 }  // namespace ui