compositor-worker: Keep worker backing thread alive for the lifetime of the compositor thread.

third_party/WebKit/Source/modules/compositorworker/CompositorWorkerThreadTest.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 "modules/compositorworker/CompositorWorkerThread.h"
 
 #include "bindings/core/v8/ScriptSourceCode.h"
 #include "bindings/core/v8/V8GCController.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/testing/DummyPageHolder.h"
@@ skipping 64 matching lines @@
     OwnPtr<WebThread> m_thread;
     TestingCompositorSupport m_compositorSupport;
 };
 
 } // namespace
 
 class CompositorWorkerThreadTest : public ::testing::Test {
 public:
     void SetUp() override
     {
         CompositorWorkerThread::resetSharedBackingThreadForTest();

[yhirano, 2016/05/19 05:35:37]

ASSERT_EQ(0, compositorWorker->workerBackingThread()->workerScriptCount());

         m_page = DummyPageHolder::create();
         m_objectProxy = TestCompositorWorkerObjectProxy::create(&m_page->document());
         m_securityOrigin = SecurityOrigin::create(KURL(ParsedURLString, "http://fake.url/"));
     }
 
     void TearDown() override
     {
         m_page.clear();
-        CompositorWorkerThread::resetSharedBackingThreadForTest();
+        CompositorWorkerThread::clearSharedBackingThread();
     }
 
     PassOwnPtr<CompositorWorkerThread> createCompositorWorker()
     {
         OwnPtr<CompositorWorkerThread> workerThread = CompositorWorkerThread::create(nullptr, *m_objectProxy, 0);
         WorkerClients* clients = nullptr;
         workerThread->start(WorkerThreadStartupData::create(
             KURL(ParsedURLString, "http://fake.url/"),
             "fake user agent",
             "//fake source code",
@@ skipping 71 matching lines @@
 
 // Tests that a new WebThread is created if all existing workers are terminated before a new worker is created.
 TEST_F(CompositorWorkerThreadTest, TerminateFirstAndCreateSecond)
 {
     // Create the first worker, wait until it is initialized, and terminate it.
     OwnPtr<CompositorWorkerThread> compositorWorker = createCompositorWorker();
     WorkerBackingThread* workerBackingThread = &compositorWorker->workerBackingThread();
     WebThreadSupportingGC* firstThread = &compositorWorker->workerBackingThread().backingThread();
     checkWorkerCanExecuteScript(compositorWorker.get());
 
-    ASSERT_EQ(1u, workerBackingThread->workerScriptCount());
+    ASSERT_EQ(2u, workerBackingThread->workerScriptCount());
     compositorWorker->terminateAndWait();
 
-    ASSERT_EQ(0u, workerBackingThread->workerScriptCount());
+    ASSERT_EQ(1u, workerBackingThread->workerScriptCount());
 
     // Create the second worker. The backing thread is same.
     compositorWorker = createCompositorWorker();
     WebThreadSupportingGC* secondThread = &compositorWorker->workerBackingThread().backingThread();
     EXPECT_EQ(firstThread, secondThread);
     checkWorkerCanExecuteScript(compositorWorker.get());
-    ASSERT_EQ(1u, workerBackingThread->workerScriptCount());
+    ASSERT_EQ(2u, workerBackingThread->workerScriptCount());
 
     compositorWorker->terminateAndWait();
 }
 
 // Tests that v8::Isolate and WebThread are correctly set-up if a worker is created while another is terminating.
 TEST_F(CompositorWorkerThreadTest, CreatingSecondDuringTerminationOfFirst)
 {
     OwnPtr<CompositorWorkerThread> firstWorker = createCompositorWorker();
     checkWorkerCanExecuteScript(firstWorker.get());
     v8::Isolate* firstIsolate = firstWorker->isolate();
     ASSERT_TRUE(firstIsolate);
 
     // Request termination of the first worker and create the second worker
     // as soon as possible.
-    EXPECT_EQ(1u, firstWorker->workerBackingThread().workerScriptCount());
+    EXPECT_EQ(2u, firstWorker->workerBackingThread().workerScriptCount());
     firstWorker->terminate();
     // We don't wait for its termination.
     // Note: We rely on the assumption that the termination steps don't run
     // on the worker thread so quickly. This could be a source of flakiness.
 
     OwnPtr<CompositorWorkerThread> secondWorker = createCompositorWorker();
 
     v8::Isolate* secondIsolate = secondWorker->isolate();
     ASSERT_TRUE(secondIsolate);
     EXPECT_EQ(firstIsolate, secondIsolate);
 
     // Verify that the isolate can run some scripts correctly in the second worker.
     checkWorkerCanExecuteScript(secondWorker.get());
     secondWorker->terminateAndWait();
 }
 
 } // namespace blink