Move RenderViewHostObserver to content/public/browser/ and put it into the content namespace.

content/browser/renderer_host/render_view_host_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_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_OBSERVER_H_
-#define CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_OBSERVER_H_
-
-#include "ipc/ipc_channel.h"
-#include "content/common/content_export.h"
-
-class GURL;
-class RenderViewHost;
-
-// An observer API implemented by classes which want to filter IPC messages from
-// RenderViewHost.
-class CONTENT_EXPORT RenderViewHostObserver : public IPC::Channel::Listener,
-                                              public IPC::Message::Sender {
- public:
-
- protected:
-  explicit RenderViewHostObserver(RenderViewHost* render_view_host);
-
-  virtual ~RenderViewHostObserver();
-
-  // Invoked after the RenderViewHost is created in the renderer process.  After
-  // this point, messages can be sent to it (or to observers in the renderer).
-  virtual void RenderViewHostInitialized();
-
-  // Invoked when the RenderViewHost is being destroyed. Gives subclasses a
-  // chance to cleanup.  The base implementation will delete the object.
-  // |render_view_host| is passed as an argument since render_view_host() will
-  // return NULL once this method enters.
-  virtual void RenderViewHostDestroyed(RenderViewHost* render_view_host);
-
-  // Notifies that a navigation is starting.
-  virtual void Navigate(const GURL& url);
-
-  // IPC::Channel::Listener implementation.
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-
-  // IPC::Message::Sender implementation.
-  virtual bool Send(IPC::Message* message) OVERRIDE;
-
-  RenderViewHost* render_view_host() const { return render_view_host_; }
-  int routing_id() { return routing_id_; }
-
- private:
-  friend class RenderViewHost;
-
-  // Invoked from RenderViewHost. Invokes RenderViewHostDestroyed and NULL out
-  // |render_view_host_|.
-  void RenderViewHostDestruction();
-
-  RenderViewHost* render_view_host_;
-
-  // The routing ID of the associated RenderViewHost.
-  int routing_id_;
-
-  DISALLOW_COPY_AND_ASSIGN(RenderViewHostObserver);
-};
-
-#endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_OBSERVER_H_