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 30 matching lines @@
     case blink::WebPermissionStatusDenied:
       return PERMISSION_STATUS_DENIED;
     case blink::WebPermissionStatusPrompt:
       return PERMISSION_STATUS_ASK;
   }
 
   NOTREACHED();
   return PERMISSION_STATUS_DENIED;
 }
 
+// PERMISSION_STATUS_NUM is only a boundary value and should never be passed
+// into this function for |status|.
 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:
+      NOTREACHED();
+      break;
   }
 
-  NOTREACHED();
   return blink::WebPermissionStatusDenied;
 }
 
 const int kNoWorkerThread = 0;
 
 }  // anonymous namespace
 
 // static
 bool PermissionDispatcher::IsObservable(blink::WebPermissionType type) {
   return type == blink::WebPermissionTypeGeolocation ||
@@ skipping 205 matching lines @@
       origin,
       current_status,
       base::Bind(&PermissionDispatcher::OnPermissionChanged,
                  base::Unretained(this),
                  type,
                  origin,
                  base::Unretained(observer)));
 }
 
 }  // namespace content