Remove testing::CloneToPassOwnPtr; it is unused.

Source/core/animation/CompositorAnimationsTest.cpp

 /*
  * Copyright (c) 2013, 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 43 matching lines @@
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
 
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 namespace blink {
 
-using ::testing::CloneToPassOwnPtr;
 using ::testing::ExpectationSet;
 using ::testing::Ref;
 using ::testing::Return;
 using ::testing::_;
 
 class AnimationCompositorAnimationsTest : public AnimationCompositorAnimationsTestBase {
 protected:
     RefPtr<TimingFunction> m_linearTimingFunction;
     RefPtr<TimingFunction> m_cubicEaseTimingFunction;
     RefPtr<TimingFunction> m_cubicCustomTimingFunction;
@@ skipping 1170 matching lines @@
     element->setLayoutObject(nullptr);
     LayoutObjectProxy::dispose(layoutObject);
 
     animation1.release();
     animation2.release();
     Heap::collectAllGarbage();
     EXPECT_TRUE(element->elementAnimations()->animations().isEmpty());
 }
 
 } // namespace blink