Make test proxy Platform objects provide currentThread().

Source/core/fetch/CachingCorrectnessTest.cpp

 /*
  * Copyright (c) 2014, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 106 matching lines @@
         FetchRequest fetchRequest(ResourceRequest(KURL(ParsedURLString, kResourceURL)), FetchInitiatorInfo());
         return m_fetcher->fetchImage(fetchRequest);
     }
 
     ResourceFetcher* fetcher() const { return m_fetcher.get(); }
 
 private:
     // A simple platform that mocks out the clock, for cache freshness testing.
     class ProxyPlatform : public blink::Platform {
     public:
-        ProxyPlatform() : m_elapsedSeconds(0.) { }
+        ProxyPlatform()
+            : m_elapsedSeconds(0.)
+            , m_platform(Platform::current())
+        {
+        }
+
+        ~ProxyPlatform()
+        {
+            blink::Platform::initialize(m_platform);
+        }
 
         void advanceClock(double seconds)
         {
             m_elapsedSeconds += seconds;
         }
 
+        virtual WebThread* currentThread() override
+        {
+            if (m_platform)
+                return m_platform->currentThread();
+
+            return nullptr;
+        }
+
     private:
         // From blink::Platform:
         virtual double currentTime()
         {
             return kOriginalRequestDateAsDouble + m_elapsedSeconds;
         }
 
         // These blink::Platform methods must be overriden to make a usable object.
         virtual void cryptographicallyRandomValues(unsigned char* buffer, size_t length) { ASSERT_NOT_REACHED(); }
         virtual const unsigned char* getTraceCategoryEnabledFlag(const char* categoryName)
         {
             return &kAConstUnsignedCharZero;
         }
 
         double m_elapsedSeconds;
+
+        Platform* m_platform;
     };
 
     virtual void SetUp()
     {
-        m_savedPlatform = blink::Platform::current();
         blink::Platform::initialize(&m_proxyPlatform);
 
         // Save the global memory cache to restore it upon teardown.
         m_globalMemoryCache = replaceMemoryCacheForTesting(MemoryCache::create());
 
         m_fetcher = ResourceFetcher::create(MockFetchContext::create());
     }
 
     virtual void TearDown()
     {
         memoryCache()->evictResources();
 
         // Yield the ownership of the global memory cache back.
         replaceMemoryCacheForTesting(m_globalMemoryCache.release());
-
-        blink::Platform::initialize(m_savedPlatform);
     }
 
-    blink::Platform* m_savedPlatform;
     ProxyPlatform m_proxyPlatform;
 
     OwnPtrWillBePersistent<MemoryCache> m_globalMemoryCache;
     RefPtrWillBePersistent<ResourceFetcher> m_fetcher;
 };
 
 TEST_F(CachingCorrectnessTest, FreshFromLastModified)
 {
     ResourceResponse fresh200Response;
     fresh200Response.setHTTPStatusCode(200);
@@ skipping 386 matching lines @@
     firstResource->setResponse(fresh200Response);
     memoryCache()->add(firstResource.get());
 
     advanceClock(500.);
 
     ResourcePtr<Resource> fetched = fetch();
     EXPECT_EQ(firstResource, fetched);
 }
 
 } // namespace