[bindings] Migrate V8TestingScope out of V8Binding.h/cpp

Source/core/animation/TimingInputTest.cpp

 // Copyright 2014 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/animation/TimingInput.h"
 
 #include "bindings/core/v8/V8AnimationTimingProperties.h"
+#include "bindings/core/v8/V8TestingScope.h"
 #include "core/animation/AnimationNodeTiming.h"
 #include "core/animation/AnimationTestHelper.h"
 #include <gtest/gtest.h>
 #include <v8.h>
 
 namespace blink {
 
 class AnimationTimingInputTest : public ::testing::Test {
 protected:
     AnimationTimingInputTest()
@@ skipping 153 matching lines @@
     EXPECT_EQ(controlTiming.fillMode, updatedTiming.fillMode);
     EXPECT_EQ(controlTiming.iterationStart, updatedTiming.iterationStart);
     EXPECT_EQ(controlTiming.iterationCount, updatedTiming.iterationCount);
     EXPECT_TRUE(std::isnan(updatedTiming.iterationDuration));
     EXPECT_EQ(controlTiming.playbackRate, updatedTiming.playbackRate);
     EXPECT_EQ(controlTiming.direction, updatedTiming.direction);
     EXPECT_EQ(*controlTiming.timingFunction, *updatedTiming.timingFunction);
 }
 
 } // namespace blink