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"
+#include "content/public/renderer/render_frame_observer.h"
+
+namespace content {
+
+class RenderFrameImpl;
+class RenderThreadBlameContext;
+
+// A blame context which represents a single render frame.
+class RenderFrameBlameContext : public base::trace_event::BlameContext,
+                                public RenderFrameObserver {
+ public:
+  RenderFrameBlameContext(RenderFrameImpl* frame);
+  ~RenderFrameBlameContext() override;
+
+  // RenderFrameObserver implementation:
+  void DidCreateNewDocument() override;
+
+ 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_