Remove dependency on PrefChangeRegistrar and renderer_preferences_util from content.

chrome/browser/renderer_host/chrome_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 "chrome/browser/renderer_host/chrome_render_view_host_observer.h"
 
 #include "chrome/browser/dom_operation_notification_details.h"
+#include "chrome/browser/net/predictor_api.h"
 #include "chrome/common/render_messages.h"
+#include "content/browser/renderer_host/render_view_host.h"
+#include "content/browser/renderer_host/render_view_host_delegate.h"
 #include "content/common/notification_service.h"
+#include "content/common/url_constants.h"
 #include "content/common/view_messages.h"
 
 ChromeRenderViewHostObserver::ChromeRenderViewHostObserver(
     RenderViewHost* render_view_host)
     : RenderViewHostObserver(render_view_host) {
 }
 
 ChromeRenderViewHostObserver::~ChromeRenderViewHostObserver() {
 }
 
+void ChromeRenderViewHostObserver::Navigate(
+    const ViewMsg_Navigate_Params& params) {
+  const GURL& url = params.url;
+  if (!render_view_host()->delegate()->IsExternalTabContainer() &&
+      (url.SchemeIs(chrome::kHttpScheme) || url.SchemeIs(chrome::kHttpsScheme)))
+    chrome_browser_net::PreconnectUrlAndSubresources(url);
+}
+
 bool ChromeRenderViewHostObserver::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ChromeRenderViewHostObserver, message)
     IPC_MESSAGE_HANDLER(ViewHostMsg_DomOperationResponse,
                         OnDomOperationResponse)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void ChromeRenderViewHostObserver::OnDomOperationResponse(
     const std::string& json_string, int automation_id) {
   DomOperationNotificationDetails details(json_string, automation_id);
   NotificationService::current()->Notify(
       NotificationType::DOM_OPERATION_RESPONSE,
       Source<RenderViewHost>(render_view_host()),
       Details<DomOperationNotificationDetails>(&details));
 }