Add builders for tracing event's structural arguments

cc/layers/layer_impl.h

Index: cc/layers/layer_impl.h
diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index 979d2e02c8c0a96ce4ce13b2de5a5c38f20ba5c3..c1ce9df5c0198be46b4ee76cf2a2cda99ffd7367 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -39,6 +39,7 @@
 namespace base {
 namespace debug {
 class ConvertableToTraceFormat;
+class TracedValue;
 }
 
 class DictionaryValue;
@@ -521,7 +522,8 @@ class CC_EXPORT LayerImpl : public LayerAnimationValueObserver,
   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
   virtual void PushPropertiesTo(LayerImpl* layer);
 
-  scoped_ptr<base::Value> AsValue() const;
+  virtual void AsValueInto(base::debug::TracedValue* dict) const;
+
   virtual size_t GPUMemoryUsageInBytes() const;
 
   void SetNeedsPushProperties();
@@ -563,8 +565,6 @@ class CC_EXPORT LayerImpl : public LayerAnimationValueObserver,
                              SkColor color,
                              float width) const;
 
-  virtual void AsValueInto(base::DictionaryValue* dict) const;
-
   void NoteLayerPropertyChanged();
   void NoteLayerPropertyChangedForSubtree();