Refactor TimeBase to post tasks. Workers to use real Idle tasks.

Source/core/fetch/ResourceTest.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/fetch/Resource.h"
 
 #include "core/fetch/ResourcePtr.h"
 #include "platform/network/ResourceRequest.h"
 #include "platform/network/ResourceResponse.h"
 #include "platform/testing/URLTestHelpers.h"
 #include "public/platform/Platform.h"
 #include "wtf/Vector.h"
 
 #include <gtest/gtest.h>
 
 using namespace blink;
 
 namespace blink {
 
 namespace {
 
 class MockPlatform final : public Platform {
 public:
-    MockPlatform() { }
+    MockPlatform() : m_oldPlatform(Platform::current()) { }
     ~MockPlatform() override { }
 
     // From blink::Platform:
     void cacheMetadata(const WebURL& url, int64, const char*, size_t) override
     {
         m_cachedURLs.append(url);
     }
     void cryptographicallyRandomValues(unsigned char* buffer, size_t length) override
     {
         ASSERT_NOT_REACHED();
     }
 
     const Vector<WebURL>& cachedURLs() const
     {
         return m_cachedURLs;
     }
 
+    WebThread* currentThread() override
+    {
+        return m_oldPlatform->currentThread();
+    }
+
 private:
+    Platform* m_oldPlatform; // NOT OWNED.
     Vector<WebURL> m_cachedURLs;
 };
 
 class AutoInstallMockPlatform {
 public:
     AutoInstallMockPlatform()
     {
         m_oldPlatform = Platform::current();
         Platform::initialize(&m_mockPlatform);
     }
@@ skipping 37 matching lines @@
 TEST(ResourceTest, SetCachedMetadata_DoesNotSendMetadataToPlatformWhenFetchedViaServiceWorker)
 {
     AutoInstallMockPlatform mock;
     OwnPtr<ResourceResponse> response(createTestResourceResponse());
     response->setWasFetchedViaServiceWorker(true);
     createTestResourceAndSetCachedMetadata(response.get());
     EXPECT_EQ(0u, mock.platform()->cachedURLs().size());
 }
 
 } // namespace blink