Fix scroll anchoring during viewport resize.

third_party/WebKit/Source/web/tests/VisualViewportTest.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 "core/frame/VisualViewport.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 1807 matching lines @@
 
     webViewImpl()->handleInputEvent(pinchUpdate);
 
     VisualViewport& visualViewport = webViewImpl()->page()->frameHost().visualViewport();
     FrameView& frameView = *webViewImpl()->mainFrameImpl()->frameView();
 
     EXPECT_FLOAT_POINT_EQ(FloatPoint(50, 50), visualViewport.location());
     EXPECT_FLOAT_POINT_EQ(FloatPoint(0, 0), frameView.scrollPositionDouble());
 }
 
+TEST_P(ParameterizedVisualViewportTest, ResizeWithScrollAnchoring)
+{
+    bool wasScrollAnchoringEnabled = RuntimeEnabledFeatures::scrollAnchoringEnabled();
+    RuntimeEnabledFeatures::setScrollAnchoringEnabled(true);
+
+    initializeWithDesktopSettings();
+    webViewImpl()->resize(IntSize(800, 600));
+
+    registerMockedHttpURLLoad("icb-relative-content.html");
+    navigateTo(m_baseURL + "icb-relative-content.html");
+
+    FrameView& frameView = *webViewImpl()->mainFrameImpl()->frameView();
+    frameView.layoutViewportScrollableArea()->setScrollPosition(DoublePoint(700, 500), ProgrammaticScroll);
+
+    webViewImpl()->resize(IntSize(400, 300));
+    EXPECT_POINT_EQ(DoublePoint(300, 200), frameView.layoutViewportScrollableArea()->scrollPositionDouble());
+
+    RuntimeEnabledFeatures::setScrollAnchoringEnabled(wasScrollAnchoringEnabled);
+}
+
 } // namespace