[Extensions] Move Feature channel code into //extensions

chrome/browser/extensions/chrome_notification_observer.cc

 // Copyright 2013 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/chrome_notification_observer.h"
 
-#include "chrome/common/extensions/features/feature_channel.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "extensions/common/extension_messages.h"
+#include "extensions/common/features/feature_channel.h"
 
 namespace extensions {
 
 ChromeNotificationObserver::ChromeNotificationObserver() {
   registrar_.Add(this,
                  content::NOTIFICATION_RENDERER_PROCESS_CREATED,
                  content::NotificationService::AllBrowserContextsAndSources());
 }
 
 ChromeNotificationObserver::~ChromeNotificationObserver() {}
 
 void ChromeNotificationObserver::OnRendererProcessCreated(
     content::RenderProcessHost* process) {
   // Extensions need to know the channel for API restrictions. Send the channel
   // to all renderers, as the non-extension renderers may have content scripts.
   process->Send(
       new ExtensionMsg_SetChannel(static_cast<int>(GetCurrentChannel())));
 }
 
 void ChromeNotificationObserver::Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) {
   DCHECK_EQ(content::NOTIFICATION_RENDERER_PROCESS_CREATED, type);
 
   OnRendererProcessCreated(
       content::Source<content::RenderProcessHost>(source).ptr());
 }
 
 }  // namespace extensions