Remove dependency on PrefChangeRegistrar and renderer_preferences_util from content.

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() {
   delete this;
 }
 
+void RenderViewHostObserver::Navigate(const ViewMsg_Navigate_Params& params) {
+}
+
 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);
   render_view_host_ = NULL;
   RenderViewHostDestroyed();
 }