Force running GC on the worker thread before the unit test exits

Source/core/workers/WorkerThreadTest.cpp

 // 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 "config.h"
 #include "core/workers/WorkerThread.h"
 
 #include "core/inspector/ConsoleMessage.h"
 #include "core/workers/WorkerReportingProxy.h"
 #include "core/workers/WorkerThreadStartupData.h"
 #include "platform/NotImplemented.h"
+#include "platform/heap/Heap.h"
 #include "public/platform/WebScheduler.h"
 #include "public/platform/WebWaitableEvent.h"
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
+#include <v8.h>
 
 using testing::_;
 using testing::AtMost;
 using testing::Invoke;
 using testing::Return;
 using testing::Mock;
 
 namespace blink {
 
 namespace {
@@ skipping 76 matching lines @@
     {
     }
 
     ~WorkerThreadForTest() override { }
 
     // WorkerThread implementation:
     WebThreadSupportingGC& backingThread() override
     {
         return *m_thread;
     }
+    void willDestroyIsolate() override
+    {
+        v8::Isolate::GetCurrent()->RequestGarbageCollectionForTesting(v8::Isolate::kFullGarbageCollection);
+        Heap::collectAllGarbage();
+        WorkerThread::willDestroyIsolate();
+    }
 
     MOCK_METHOD1(doIdleGc, bool(double deadlineSeconds));
 
     PassRefPtrWillBeRawPtr<WorkerGlobalScope> createWorkerGlobalScope(PassOwnPtr<WorkerThreadStartupData> startupData) override
     {
         return adoptRefWillBeNoop(new FakeWorkerGlobalScope(startupData->m_scriptURL, startupData->m_userAgent, this, startupData->m_starterOrigin, startupData->m_workerClients.release()));
     }
 
     void waitUntilScriptLoaded()
     {
@@ skipping 209 matching lines @@
 
     completion->wait();
 
     // Make sure doIdleGc has not been called by this stage.
     Mock::VerifyAndClearExpectations(m_workerThread.get());
 
     m_workerThread->terminateAndWait();
 }
 
 } // namespace blink