Implement frame attribution (FrameBlamer)

content/renderer/render_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_RENDER_FRAME_BLAME_CONTEXT_H_
+#define CONTENT_RENDERER_RENDER_FRAME_BLAME_CONTEXT_H_
+
+#include "base/trace_event/blame_context.h"
+
+namespace content {
+
+class RenderThreadBlameContext;
+
+// A blame context which represents a single render frame.
+class RenderFrameBlameContext : public base::trace_event::BlameContext {
+ public:
+  // Constructor for a top-level frame.
+  RenderFrameBlameContext(int routing_id,
+                          const RenderThreadBlameContext& parent);
+
+  // Constructor for a child frame.
+  RenderFrameBlameContext(int routing_id,
+                          const RenderFrameBlameContext& parent);
+
+  void set_url(const std::string& url) { url_ = url; }
+
+ protected:
+  void AsValueInto(base::trace_event::TracedValue* state) override;
+
+ private:
+  std::string url_;
+
+  DISALLOW_COPY_AND_ASSIGN(RenderFrameBlameContext);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_RENDER_FRAME_BLAME_CONTEXT_H_