Add a RenderProcessObserver. For now this will be primarily used to filter control messages, so ...

content/renderer/render_process_observer.h

+// Copyright (c) 2011 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_PROCESS_OBSERVER_H_
+#define CONTENT_RENDERER_RENDER_PROCESS_OBSERVER_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "ipc/ipc_message.h"
+
+// Base class for objects that want to filter control IPC messages.
+class RenderProcessObserver {
+ public:
+  virtual ~RenderProcessObserver();
+
+  // Allows filtering of control messages.
+  virtual bool OnControlMessageReceived(const IPC::Message& message);
+
+  // Notification that the render process is shutting down.
+  virtual void OnRenderProcessShutdown();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RenderProcessObserver);
+};
+
+#endif  // CONTENT_RENDERER_RENDER_PROCESS_OBSERVER_H_