Move PageTransition into content namespace. While I'm touching all these files, I've also updated...

chrome/browser/extensions/extension_host.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/extensions/extension_host.h"
 
 #include <list>
 
 #include "base/memory/singleton.h"
 #include "base/message_loop.h"
@@ skipping 316 matching lines @@
   DCHECK_EQ(render_view_host_, render_view_host);
   NotificationService::current()->Notify(
       chrome::NOTIFICATION_EXTENSION_PROCESS_TERMINATED,
       Source<Profile>(profile_),
       Details<ExtensionHost>(this));
 }
 
 void ExtensionHost::DidNavigate(RenderViewHost* render_view_host,
     const ViewHostMsg_FrameNavigate_Params& params) {
   // We only care when the outer frame changes.
-  if (!PageTransition::IsMainFrame(params.transition))
+  if (!content::PageTransitionIsMainFrame(params.transition))
     return;
 
   url_ = params.url;
 }
 
 void ExtensionHost::InsertInfobarCSS() {
   DCHECK(!is_background_page());
 
   static const base::StringPiece css(
       ResourceBundle::GetSharedInstance().GetRawDataResource(
@@ skipping 446 matching lines @@
 void ExtensionHost::RenderViewCreated(RenderViewHost* render_view_host) {
   if (view_.get())
     view_->RenderViewCreated();
 
   if (extension_host_type_ == chrome::VIEW_TYPE_EXTENSION_POPUP ||
       extension_host_type_ == chrome::VIEW_TYPE_EXTENSION_INFOBAR) {
         render_view_host->EnablePreferredSizeMode(
             kPreferredSizeWidth | kPreferredSizeHeightThisIsSlow);
   }
 }