Introduce Platform::setCurrentPlatformForTesting

third_party/WebKit/Source/platform/scroll/ScrollableAreaTest.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 "platform/scroll/ScrollableArea.h"
 
 #include "platform/graphics/Color.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "platform/scroll/ScrollbarThemeMock.h"
@@ skipping 57 matching lines @@
         : m_maximumScrollPosition(maximumScrollPosition) { }
 
     IntPoint m_scrollPosition;
     IntPoint m_maximumScrollPosition;
 };
 
 } // namespace
 
 class ScrollableAreaTest : public testing::Test {
 public:
-    ScrollableAreaTest() : m_oldPlatform(nullptr) { }
+    ScrollableAreaTest() { }
 
     void SetUp() override
     {
-        m_oldPlatform = Platform::current();
         TestingPlatformSupport::Config config;
-        config.compositorSupport = m_oldPlatform->compositorSupport();
+        config.compositorSupport = Platform::current()->compositorSupport();
         m_fakePlatform = adoptPtr(new TestingPlatformSupportWithMockScheduler(config));
-        Platform::initialize(m_fakePlatform.get());
     }
 
     void TearDown() override
     {
-        Platform::initialize(m_oldPlatform);
         m_fakePlatform = nullptr;
     }
 
 private:
     OwnPtr<TestingPlatformSupportWithMockScheduler> m_fakePlatform;
-    Platform* m_oldPlatform; // Not owned.
 };
 
 TEST_F(ScrollableAreaTest, ScrollAnimatorCurrentPositionShouldBeSync)
 {
     OwnPtrWillBeRawPtr<MockScrollableArea> scrollableArea = MockScrollableArea::create(IntPoint(0, 100));
     scrollableArea->setScrollPosition(IntPoint(0, 10000), CompositorScroll);
     EXPECT_EQ(100.0, scrollableArea->scrollAnimator().currentPosition().y());
 }
 
 namespace {
@@ skipping 178 matching lines @@
     OwnPtrWillBeRawPtr<MockScrollableArea> scrollableArea = MockScrollableArea::create(IntPoint(0, 100));
 
     EXPECT_EQ(ScrollbarOverlayStyleDefault, scrollableArea->getScrollbarOverlayStyle());
     scrollableArea->recalculateScrollbarOverlayStyle(Color(34, 85, 51));
     EXPECT_EQ(ScrollbarOverlayStyleLight, scrollableArea->getScrollbarOverlayStyle());
     scrollableArea->recalculateScrollbarOverlayStyle(Color(236, 143, 185));
     EXPECT_EQ(ScrollbarOverlayStyleDefault, scrollableArea->getScrollbarOverlayStyle());
 }
 
 } // namespace blink