ServiceWorker: Enable UseCounter for ServiceWorkerGlobalScope

third_party/WebKit/Source/modules/serviceworkers/NavigatorServiceWorker.cpp

 // 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 "modules/serviceworkers/NavigatorServiceWorker.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Navigator.h"
 #include "modules/serviceworkers/ServiceWorkerContainer.h"
 
 namespace blink {
 
 NavigatorServiceWorker::NavigatorServiceWorker(Navigator& navigator) {}
 
 NavigatorServiceWorker* NavigatorServiceWorker::from(Document& document) {
   if (!document.frame() || !document.frame()->domWindow())
     return nullptr;
   Navigator& navigator = *document.frame()->domWindow()->navigator();
   return &from(navigator);
 }
 
 NavigatorServiceWorker& NavigatorServiceWorker::from(Navigator& navigator) {
   NavigatorServiceWorker* supplement = toNavigatorServiceWorker(navigator);
   if (!supplement) {
     supplement = new NavigatorServiceWorker(navigator);
     provideTo(navigator, supplementName(), supplement);
-    if (navigator.frame() &&
-        navigator.frame()
-            ->securityContext()
-            ->getSecurityOrigin()
-            ->canAccessServiceWorkers()) {
-      // Initialize ServiceWorkerContainer too.
-      supplement->serviceWorker(navigator.frame(), ASSERT_NO_EXCEPTION);
-    }
+  }
+  if (navigator.frame() &&
+      navigator.frame()
+          ->securityContext()
+          ->getSecurityOrigin()
+          ->canAccessServiceWorkers()) {
+    // Ensure ServiceWorkerContainer. It can be cleared regardless of
+    // |supplement|. See comments in NavigatorServiceWorker::serviceWorker() for
+    // details.
+    supplement->serviceWorker(navigator.frame(), ASSERT_NO_EXCEPTION);
   }
   return *supplement;
 }
 
 NavigatorServiceWorker* NavigatorServiceWorker::toNavigatorServiceWorker(
     Navigator& navigator) {
   return static_cast<NavigatorServiceWorker*>(
       Supplement<Navigator>::from(navigator, supplementName()));
 }
 
@@ skipping 69 matching lines @@
 void NavigatorServiceWorker::clearServiceWorker() {
   m_serviceWorker = nullptr;
 }
 
 DEFINE_TRACE(NavigatorServiceWorker) {
   visitor->trace(m_serviceWorker);
   Supplement<Navigator>::trace(visitor);
 }
 
 }  // namespace blink