Use refs for non-null GraphicsContext, Scrollbar, etc. in scrollbar related code

third_party/WebKit/Source/web/LinkHighlightImplTest.cpp

 /*
  * Copyright (C) 2012 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:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 183 matching lines @@
 
     webViewImpl->enableTapHighlightAtPoint(targetedEvent);
     ASSERT_TRUE(webViewImpl->linkHighlight(0));
 
     GraphicsLayer* highlightLayer = webViewImpl->linkHighlight(0)->currentGraphicsLayerForTesting();
     ASSERT_TRUE(highlightLayer);
     EXPECT_TRUE(highlightLayer->linkHighlight(0));
 
     // Mimic the logic from RenderWidget::Close:
     webViewImpl->willCloseLayerTreeView();
-    webViewClient.clear();
     webViewHelper.reset();
 
     Platform::current()->unitTestSupport()->unregisterAllMockedURLs();
 }
 
 TEST(LinkHighlightImplTest, multipleHighlights)
 {
     const std::string baseURL("http://www.test.com/");
     const std::string fileName("test_touch_link_highlight.html");
 
@@ skipping 17 matching lines @@
     IntRect boundingBox(touchEvent.x - touchEvent.data.tap.width / 2, touchEvent.y - touchEvent.data.tap.height / 2, touchEvent.data.tap.width, touchEvent.data.tap.height);
     findGoodTouchTargets(boundingBox, webViewImpl->mainFrameImpl()->frame(), goodTargets, highlightNodes);
 
     webViewImpl->enableTapHighlights(highlightNodes);
     EXPECT_EQ(2U, webViewImpl->numLinkHighlights());
 
     Platform::current()->unitTestSupport()->unregisterAllMockedURLs();
 }
 
 } // namespace blink