Add a feature flag for enabling subscription restrictions

chrome/browser/push_messaging/push_messaging_service_impl.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_PUSH_MESSAGING_PUSH_MESSAGING_SERVICE_IMPL_H_
 #define CHROME_BROWSER_PUSH_MESSAGING_PUSH_MESSAGING_SERVICE_IMPL_H_
 
 #include <stdint.h>
 #include <set>
 #include <vector>
@@ skipping 53 matching lines @@
                  const gcm::IncomingMessage& message) override;
   void OnMessagesDeleted(const std::string& app_id) override;
   void OnSendError(
       const std::string& app_id,
       const gcm::GCMClient::SendErrorDetails& send_error_details) override;
   void OnSendAcknowledged(const std::string& app_id,
                           const std::string& message_id) override;
   bool CanHandle(const std::string& app_id) const override;
 
   // content::PushMessagingService implementation:
-  GURL GetPushEndpoint() override;
+  GURL GetEndpoint(bool standard_protocol) const override;
   void SubscribeFromDocument(
       const GURL& requesting_origin,
       int64_t service_worker_registration_id,
       int renderer_id,
       int render_frame_id,
       const content::PushSubscriptionOptions& options,
       const content::PushMessagingService::RegisterCallback& callback) override;
   void SubscribeFromWorker(
       const GURL& requesting_origin,
       int64_t service_worker_registration_id,
@@ skipping 156 matching lines @@
   MessageDispatchedCallback message_dispatched_callback_for_testing_;
 
   scoped_ptr<PushMessagingServiceObserver> push_messaging_service_observer_;
 
   base::WeakPtrFactory<PushMessagingServiceImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PushMessagingServiceImpl);
 };
 
 #endif  // CHROME_BROWSER_PUSH_MESSAGING_PUSH_MESSAGING_SERVICE_IMPL_H_