[Worker] Call prepareForShutdown ASAP when terminated forcibly

third_party/WebKit/Source/core/loader/ThreadableLoaderTest.cpp

 // Copyright 2016 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 "core/loader/ThreadableLoader.h"
 
 #include "core/dom/ExecutionContextTask.h"
 #include "core/fetch/MemoryCache.h"
 #include "core/fetch/ResourceLoaderOptions.h"
 #include "core/loader/DocumentThreadableLoader.h"
@@ skipping 238 matching lines @@
     }
 
     void onServeRequests() override
     {
         testing::runPendingTasks();
     }
 
     void onTearDown() override
     {
         postTaskToWorkerGlobalScope(BLINK_FROM_HERE, createCrossThreadTask(&WorkerThreadableLoaderTestHelper::clearLoader, crossThreadUnretained(this)));
+        WaitableEvent event;
+        postTaskToWorkerGlobalScope(BLINK_FROM_HERE, createCrossThreadTask(&WaitableEvent::signal, crossThreadUnretained(&event)));
+        event.wait();
         m_workerThread->terminateAndWait();
 
         // Needed to clean up the things on the main thread side and
         // avoid Resource leaks.
         testing::runPendingTasks();
 
         m_workerThread->workerLoaderProxy()->detachProvider(this);
     }
 
 private:
@@ skipping 599 matching lines @@
     // test is not saying that didFailAccessControlCheck should be dispatched
     // synchronously, but is saying that even when a response is served
     // synchronously it should not lead to a crash.
     startLoader(KURL(KURL(), "about:blank"));
     callCheckpoint(2);
 }
 
 } // namespace
 
 } // namespace blink