Collecting statistics on iframe permissions use.

content/child/permissions/permission_dispatcher.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/permissions/permission_dispatcher.h"
 
 #include "base/callback.h"
 #include "content/child/worker_task_runner.h"
 #include "content/public/common/service_registry.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
@@ skipping 38 matching lines @@
 }
 
 blink::WebPermissionStatus GetWebPermissionStatus(PermissionStatus status) {
   switch (status) {
     case PERMISSION_STATUS_GRANTED:
       return blink::WebPermissionStatusGranted;
     case PERMISSION_STATUS_DENIED:
       return blink::WebPermissionStatusDenied;
     case PERMISSION_STATUS_ASK:
       return blink::WebPermissionStatusPrompt;
+    case PERMISSION_STATUS_NUM:
+      // PERMISSION_STATUS_NUM should never be passed into this function.

[jww, 2015/07/07 21:14:23]

It appears you didn't add a NOTREACHED into the switch() statement.

Additionally, please remove the comment here in the background_sync_provider;
this is self evident. What I would like to see is a comment in the header file
or at least before the function definition specifying what values the
PermissionStatus arguments can take (namely, it cannot be
PERMISSION_STATUS_NUM). The idea is that this is the API developers will use,
and it should be clear when they look at the definition what they can and cannot
put in as a value.

[keenanb, 2015/07/08 00:37:21]

sort of done. (this function is local to this file.)

+      break;
   }
 
   NOTREACHED();
   return blink::WebPermissionStatusDenied;
 }
 
 const int kNoWorkerThread = 0;
 
 }  // anonymous namespace
 
@@ skipping 208 matching lines @@
       origin,
       current_status,
       base::Bind(&PermissionDispatcher::OnPermissionChanged,
                  base::Unretained(this),
                  type,
                  origin,
                  base::Unretained(observer)));
 }
 
 }  // namespace content