Made layout viewport scroll updates from compositor work like ordinary layers.

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

 /*
  * Copyright (C) 2010 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 5647 matching lines @@
 
     // Make sure we initialize to minimum scale, even if the window size
     // only becomes available after the load begins.
     FrameTestHelpers::WebViewHelper webViewHelper;
     webViewHelper.initializeAndLoad(m_baseURL + "long_scroll.html", true, &client);
     webViewHelper.resize(WebSize(1000, 1000));
 
     WebLocalFrameImpl* frameImpl = webViewHelper.webViewImpl()->mainFrameImpl();
     DocumentLoader::InitialScrollState& initialScrollState =
         frameImpl->frame()->loader().documentLoader()->initialScrollState();
+    GraphicsLayer* frameViewLayer = frameImpl->frameView()->layerForScrolling();
 
     EXPECT_FALSE(client.wasFrameScrolled());
     EXPECT_FALSE(initialScrollState.wasScrolledByUser);
 
     // Do a compositor scroll, verify that this is counted as a user scroll.
-    webViewHelper.webViewImpl()->applyViewportDeltas(WebFloatSize(), WebFloatSize(0, 1), WebFloatSize(), 1.7f, 0);
+    frameViewLayer->platformLayer()->setScrollPositionDouble(WebDoublePoint(0, 1));
+    frameViewLayer->didScroll();
+    webViewHelper.webViewImpl()->applyViewportDeltas(WebFloatSize(), WebFloatSize(), WebFloatSize(), 1.7f, 0);
     EXPECT_TRUE(client.wasFrameScrolled());
     EXPECT_TRUE(initialScrollState.wasScrolledByUser);
 
     client.reset();
     initialScrollState.wasScrolledByUser = false;
 
     // The page scale 1.0f and scroll.
-    webViewHelper.webViewImpl()->applyViewportDeltas(WebFloatSize(), WebFloatSize(0, 1), WebFloatSize(), 1.0f, 0);
+    frameViewLayer->platformLayer()->setScrollPositionDouble(WebDoublePoint(0, 2));
+    frameViewLayer->didScroll();
+    webViewHelper.webViewImpl()->applyViewportDeltas(WebFloatSize(), WebFloatSize(), WebFloatSize(), 1.0f, 0);
     EXPECT_TRUE(client.wasFrameScrolled());
     EXPECT_TRUE(initialScrollState.wasScrolledByUser);
     client.reset();
     initialScrollState.wasScrolledByUser = false;
 
     // No scroll event if there is no scroll delta.
+    frameViewLayer->didScroll();
     webViewHelper.webViewImpl()->applyViewportDeltas(WebFloatSize(), WebFloatSize(), WebFloatSize(), 1.0f, 0);
     EXPECT_FALSE(client.wasFrameScrolled());
     EXPECT_FALSE(initialScrollState.wasScrolledByUser);
     client.reset();
 
     // Non zero page scale and scroll.
-    webViewHelper.webViewImpl()->applyViewportDeltas(WebFloatSize(), WebFloatSize(9, 13), WebFloatSize(), 0.6f, 0);
+    frameViewLayer->platformLayer()->setScrollPositionDouble(WebDoublePoint(9, 15));
+    frameViewLayer->didScroll();
+    webViewHelper.webViewImpl()->applyViewportDeltas(WebFloatSize(), WebFloatSize(), WebFloatSize(), 0.6f, 0);
     EXPECT_TRUE(client.wasFrameScrolled());
     EXPECT_TRUE(initialScrollState.wasScrolledByUser);
     client.reset();
     initialScrollState.wasScrolledByUser = false;
 
     // Programmatic scroll.
     frameImpl->executeScript(WebScriptSource("window.scrollTo(0, 20);"));
     EXPECT_TRUE(client.wasFrameScrolled());
     EXPECT_FALSE(initialScrollState.wasScrolledByUser);
     client.reset();
@@ skipping 3108 matching lines @@
     request.setRequestorOrigin(WebSecurityOrigin::createUnique());
     helper.webViewImpl()->mainFrame()->toWebLocalFrame()->loadRequest(request);
 
     // Normally, the result of the JS url replaces the existing contents on the
     // Document. However, if the JS triggers a navigation, the contents should
     // not be replaced.
     EXPECT_EQ("", toLocalFrame(helper.webViewImpl()->page()->mainFrame())->document()->documentElement()->innerText());
 }
 
 } // namespace blink