Trace LayoutObject src attributes and parent frames

content/renderer/frame_blame_context.h

 // Copyright 2016 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 CONTENT_RENDERER_FRAME_BLAME_CONTEXT_H_
 #define CONTENT_RENDERER_FRAME_BLAME_CONTEXT_H_
 
 #include "base/trace_event/blame_context.h"
 
 namespace content {
 
 class RenderFrameImpl;
 class RenderThreadBlameContext;
 
 // A blame context which represents a single render frame.
 class FrameBlameContext : public base::trace_event::BlameContext {
  public:
   FrameBlameContext(RenderFrameImpl* frame, RenderFrameImpl* parent_frame);
   ~FrameBlameContext() override;
 
+ protected:
+  void AsValueInto(base::trace_event::TracedValue* value) override;
+
+ private:
+  RenderFrameImpl* frame_;
+
   DISALLOW_COPY_AND_ASSIGN(FrameBlameContext);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_FRAME_BLAME_CONTEXT_H_