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

chrome/browser/extensions/extension_process_manager.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 "base/bind.h"
 #include "base/command_line.h"
 #include "chrome/browser/extensions/extension_process_manager.h"
 
 #include "chrome/browser/ui/browser_window.h"
 #include "content/browser/browsing_instance.h"
@@ skipping 201 matching lines @@
 
   // Force the options page to open in non-OTR window, because it won't be
   // able to save settings from OTR.
   if (!browser || browser->profile()->IsOffTheRecord()) {
     Profile* profile =
         Profile::FromBrowserContext(browsing_instance_->browser_context());
     browser = Browser::GetOrCreateTabbedBrowser(profile->GetOriginalProfile());
   }
 
   browser->OpenURL(extension->options_url(), GURL(), SINGLETON_TAB,
-                   PageTransition::LINK);
+                   content::PAGE_TRANSITION_LINK);
   browser->window()->Show();
   static_cast<RenderViewHostDelegate*>(browser->GetSelectedTabContents())->
       Activate();
 }
 
 ExtensionHost* ExtensionProcessManager::GetBackgroundHostForExtension(
     const Extension* extension) {
   for (ExtensionHostSet::iterator iter = background_hosts_.begin();
        iter != background_hosts_.end(); ++iter) {
     ExtensionHost* host = *iter;
@@ skipping 358 matching lines @@
         if (service && service->is_ready())
           CreateBackgroundHostsForProfileStartup(this, service->extensions());
       }
       break;
     }
     default:
       ExtensionProcessManager::Observe(type, source, details);
       break;
   }
 }