More regular Platform implementations in unit tests (reland.)

third_party/WebKit/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp

Index: third_party/WebKit/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp b/third_party/WebKit/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp
index 4187ec2b13329c4a4c097daf0d82170c6288bc21..e504997a7fc9aa080b5763e2d2512cbfc5c827db 100644
--- a/third_party/WebKit/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp
+++ b/third_party/WebKit/Source/platform/graphics/RecordingImageBufferSurfaceTest.cpp
@@ -9,6 +9,7 @@
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/graphics/ImageBufferClient.h"
 #include "platform/graphics/UnacceleratedImageBufferSurface.h"
+#include "platform/testing/TestingPlatformSupport.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebTaskRunner.h"
 #include "public/platform/WebThread.h"
@@ -236,24 +237,13 @@ namespace {
 // for the current thread. The Mock thread is capable of queuing a single non-delayed task
 // and registering a single task observer. The run loop exits immediately after running
 // the single task.
-class AutoInstallCurrentThreadPlatformMock {
-public:
-    AutoInstallCurrentThreadPlatformMock()
-    {
-        m_oldPlatform = Platform::current();
-        Platform::initialize(&m_mockPlatform);
-    }
-
-    ~AutoInstallCurrentThreadPlatformMock()
-    {
-        Platform::initialize(m_oldPlatform);
-    }
 
-    void enterRunLoop()
-    {
-        m_mockPlatform.enterRunLoop();
-    }
+class CurrentThreadPlatformMock : public TestingPlatformSupport {
+public:
+    CurrentThreadPlatformMock() { }
+    WebThread* currentThread() override { return &m_currentThread; }
 
+    void enterRunLoop() { m_currentThread.enterRunLoop(); }
 private:
     class MockWebTaskRunner : public WebTaskRunner {
     public:
@@ -335,22 +325,7 @@ private:
         TaskObserver* m_taskObserver;
     };
 
-    class CurrentThreadPlatformMock : public Platform {
-    public:
-        CurrentThreadPlatformMock() { }
-        virtual void cryptographicallyRandomValues(unsigned char* buffer, size_t length)
-        {
-            RELEASE_ASSERT_NOT_REACHED();
-        }
-        WebThread* currentThread() override { return &m_currentThread; }
-
-        void enterRunLoop() { m_currentThread.enterRunLoop(); }
-    private:
-        CurrentThreadMock m_currentThread;
-    };
-
-    CurrentThreadPlatformMock m_mockPlatform;
-    Platform* m_oldPlatform;
+    CurrentThreadMock m_currentThread;
 };
 
 } // anonymous namespace
@@ -366,7 +341,7 @@ class TestWrapperTask_ ## TEST_METHOD : public WebTaskRunner::Task {
 
 #define CALL_TEST_TASK_WRAPPER(TEST_METHOD)                                                               \
     {                                                                                                     \
-        AutoInstallCurrentThreadPlatformMock ctpm;                                                        \
+        CurrentThreadPlatformMock ctpm;                                                                   \
         Platform::current()->currentThread()->taskRunner()->postTask(BLINK_FROM_HERE, new TestWrapperTask_ ## TEST_METHOD(this)); \
         ctpm.enterRunLoop();                                      \
     }