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

chrome/browser/ui/cocoa/extensions/extension_action_context_menu.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/extensions/extension_action_context_menu.h"
 
 #include "base/sys_string_conversions.h"
 #include "base/task.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
@@ skipping 222 matching lines @@
 - (void)dispatch:(id)menuItem {
   Browser* browser = BrowserList::FindBrowserWithProfile(profile_);
   if (!browser)
     return;
 
   NSMenuItem* item = (NSMenuItem*)menuItem;
   switch ([item tag]) {
     case kExtensionContextName: {
       GURL url(std::string(extension_urls::kGalleryBrowsePrefix) +
                std::string("/detail/") + extension_->id());
-      browser->OpenURL(url, GURL(), NEW_FOREGROUND_TAB, PageTransition::LINK);
+      browser->OpenURL(
+          url, GURL(), NEW_FOREGROUND_TAB, content::PAGE_TRANSITION_LINK);
       break;
     }
     case kExtensionContextOptions: {
       DCHECK(!extension_->options_url().is_empty());
       profile_->GetExtensionProcessManager()->OpenOptionsPage(extension_,
                                                               browser);
       break;
     }
     case kExtensionContextDisable: {
       ExtensionService* extensionService = profile_->GetExtensionService();
@@ skipping 62 matching lines @@
   }
   return YES;
 }
 
 - (void)invalidateProfile {
   observer_.reset();
   profile_ = NULL;
 }
 
 @end