Push registration should read a "gcm_user_visible_only" key from the Manifest.

chrome/browser/services/gcm/push_messaging_service_impl.cc

 // 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.
 
 #include "chrome/browser/services/gcm/push_messaging_service_impl.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 189 matching lines @@
 void PushMessagingServiceImpl::OnSendAcknowledged(
     const std::string& app_id,
     const std::string& message_id) {
   NOTREACHED() << "The Push API shouldn't have sent messages upstream";
 }
 
 void PushMessagingServiceImpl::Register(
     const GURL& origin,
     int64 service_worker_registration_id,
     const std::string& sender_id,
+    bool user_visible_only,
     int renderer_id,
     int render_frame_id,
     bool user_gesture,
     const content::PushMessagingService::RegisterCallback& callback) {
   if (!gcm_profile_service_->driver()) {
     NOTREACHED() << "There is no GCMDriver. Has GCMProfileService shut down?";
   }
 
   PushMessagingApplicationId application_id =
       PushMessagingApplicationId(origin, service_worker_registration_id);
@@ skipping 38 matching lines @@
   gcm::PushMessagingPermissionContext* permission_context =
       gcm::PushMessagingPermissionContextFactory::GetForProfile(profile_);
 
   if (permission_context == NULL) {
     RegisterEnd(callback,
                 std::string(),
                 content::PUSH_REGISTRATION_STATUS_PERMISSION_DENIED);
     return;
   }
 
+  // TODO(miguelg): Consider the value of |user_visible_only| when making
+  // the permission request.
   permission_context->RequestPermission(
       web_contents,
       id,
       embedder,
       user_gesture,
       base::Bind(&PushMessagingServiceImpl::DidRequestPermission,
                  weak_factory_.GetWeakPtr(),
                  application_id,
                  sender_id,
                  callback));
@@ skipping 68 matching lines @@
       application_id.ToString(),
       sender_ids,
       base::Bind(&PushMessagingServiceImpl::DidRegister,
                  weak_factory_.GetWeakPtr(),
                  register_callback));
 }
 
 // TODO(johnme): Unregister should call DecreasePushRegistrationCount.
 
 }  // namespace gcm