Use mocked scrollbar in webkit unit tests

third_party/WebKit/Source/web/tests/ProgrammaticScrollTest.cpp

 #include "config.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/LayoutView.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/FrameLoader.h"
 #include "platform/testing/URLTestHelpers.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebUnitTestSupport.h"
 #include "public/web/WebFrame.h"
@@ skipping 27 matching lines @@
 
 protected:
 
     void registerMockedHttpURLLoad(const std::string& fileName)
     {
         URLTestHelpers::registerMockedURLFromBaseURL(WebString::fromUTF8(m_baseURL.c_str()), WebString::fromUTF8(fileName.c_str()));
     }
 
     std::string m_baseURL;
     MockWebFrameClient m_mockWebFrameClient;
+    FrameTestHelpers::UseMockScrollbarSettings m_mockScrollbarSettings;
 };
 
 TEST_F(ProgrammaticScrollTest, RestoreScrollPositionAndViewStateWithScale)
 {
     registerMockedHttpURLLoad("long_scroll.html");
 
     FrameTestHelpers::WebViewHelper webViewHelper;
     WebView* webView = webViewHelper.initializeAndLoad(m_baseURL + "long_scroll.html", true, 0, 0);
     webView->resize(WebSize(1000, 1000));
     webView->layout();
@@ skipping 39 matching lines @@
 
     // FrameLoader::restoreScrollPositionAndViewState flows differently if scale is zero.
     loader.restoreScrollPositionAndViewState();
 
     // Expect that only the scroll position was restored.
     EXPECT_EQ(3.0f, webViewImpl->pageScaleFactor());
     EXPECT_EQ(400, webViewImpl->mainFrameImpl()->scrollOffset().height);
 }
 
 } // namespace blink