Collecting statistics on iframe permissions use.

content/child/background_sync/background_sync_provider.cc

 // Copyright 2015 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 "content/child/background_sync/background_sync_provider.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/child/background_sync/background_sync_type_converters.h"
 #include "content/child/service_worker/web_service_worker_registration_impl.h"
@@ skipping 236 matching lines @@
                                   "Background Sync is disabled."));
       break;
     case BACKGROUND_SYNC_ERROR_NO_SERVICE_WORKER:
       callbacks->onError(
           new blink::WebSyncError(blink::WebSyncError::ErrorTypeUnknown,
                                   "No service worker is active."));
       break;
   }
 }
 
 void BackgroundSyncProvider::GetPermissionStatusCallback(

[jww, 2015/07/08 15:53:58]

Sorry to beat on a dead horse here, but can you put a comment above here about
the values |status| is allowed to take? I know this isn't visible outside the
file, but if anyone comes and modifies your code later and uses this function,
it would be good to make the API as clear as possibly.

[jww, 2015/07/08 15:55:09]

(Although if you make mlamouri's change, then I think all of these comments can
disappear completely, right?)

[keenanb, 2015/07/08 22:31:52]

yeah. i've disappeared them in celebration.

     scoped_ptr<blink::WebSyncGetPermissionStatusCallbacks> callbacks,
     BackgroundSyncError error,
     PermissionStatus status) {
   // TODO(iclelland): Determine the correct error message to return in each case
   switch (error) {
     case BACKGROUND_SYNC_ERROR_NONE:
       switch (status) {
         case PERMISSION_STATUS_GRANTED:
           callbacks->onSuccess(new blink::WebSyncPermissionStatus(
               blink::WebSyncPermissionStatusGranted));
           break;
         case PERMISSION_STATUS_DENIED:
           callbacks->onSuccess(new blink::WebSyncPermissionStatus(
               blink::WebSyncPermissionStatusDenied));
           break;
         case PERMISSION_STATUS_ASK:
           callbacks->onSuccess(new blink::WebSyncPermissionStatus(
               blink::WebSyncPermissionStatusPrompt));
           break;
+        case PERMISSION_STATUS_NUM:
+          NOTREACHED();
+          break;
       }
       break;
     case BACKGROUND_SYNC_ERROR_NOT_FOUND:
       // This error should never be returned from
       // BackgroundSyncManager::GetPermissionStatus
       NOTREACHED();
       break;
     case BACKGROUND_SYNC_ERROR_STORAGE:
       callbacks->onError(
           new blink::WebSyncError(blink::WebSyncError::ErrorTypeUnknown,
@@ skipping 10 matching lines @@
 BackgroundSyncServicePtr&
 BackgroundSyncProvider::GetBackgroundSyncServicePtr() {
   if (!background_sync_service_.get()) {
     service_registry_->ConnectToRemoteService(
         mojo::GetProxy(&background_sync_service_));
   }
   return background_sync_service_;
 }
 
 }  // namespace content