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

content/browser/renderer_host/render_view_host_observer.cc

-// 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.
-
-#include "content/browser/renderer_host/render_view_host_observer.h"
-
-#include "content/browser/renderer_host/render_view_host.h"
-
-RenderViewHostObserver::RenderViewHostObserver(RenderViewHost* render_view_host)
-    : render_view_host_(render_view_host),
-      routing_id_(render_view_host->routing_id()) {
-  render_view_host_->AddObserver(this);
-}
-
-RenderViewHostObserver::~RenderViewHostObserver() {
-  if (render_view_host_)
-    render_view_host_->RemoveObserver(this);
-}
-
-void RenderViewHostObserver::RenderViewHostInitialized() {
-}
-
-void RenderViewHostObserver::RenderViewHostDestroyed(RenderViewHost* rvh) {
-  delete this;
-}
-
-void RenderViewHostObserver::Navigate(const GURL& url) {
-}
-
-bool RenderViewHostObserver::OnMessageReceived(const IPC::Message& message) {
-  return false;
-}
-
-bool RenderViewHostObserver::Send(IPC::Message* message) {
-  if (!render_view_host_) {
-    delete message;
-    return false;
-  }
-
-  return render_view_host_->Send(message);
-}
-
-void RenderViewHostObserver::RenderViewHostDestruction() {
-  render_view_host_->RemoveObserver(this);
-  RenderViewHost* rvh = render_view_host_;
-  render_view_host_ = NULL;
-  RenderViewHostDestroyed(rvh);
-}