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

chrome/browser/ui/cocoa/history_menu_cocoa_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/history_menu_cocoa_controller.h"
 
 #include "base/memory/scoped_vector.h"
 #include "chrome/app/chrome_command_ids.h"  // IDC_HISTORY_MENU
 #import "chrome/browser/app_controller_mac.h"
 #include "chrome/browser/history/history.h"
@@ skipping 30 matching lines @@
   // If this item can be restored using TabRestoreService, do so. Otherwise,
   // just load the URL.
   TabRestoreService* service =
       TabRestoreServiceFactory::GetForProfile(bridge_->profile());
   if (node->session_id && service) {
     service->RestoreEntryById(browser->tab_restore_service_delegate(),
         node->session_id, false);
   } else {
     DCHECK(node->url.is_valid());
     browser->OpenURL(node->url, GURL(), disposition,
-                     PageTransition::AUTO_BOOKMARK);
+                     content::PAGE_TRANSITION_AUTO_BOOKMARK);
   }
 }
 
 - (IBAction)openHistoryMenuItem:(id)sender {
   const HistoryMenuBridge::HistoryItem* item =
       bridge_->HistoryItemForMenuItem(sender);
   [self openURLForItem:item];
 }
 
 @end  // HistoryMenuCocoaController