Don't include scroll offset in offsetFromLayoutObject for scrolling contents layers.

third_party/WebKit/Source/web/LinkHighlightImpl.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
@@ skipping 53 matching lines @@
 
 PassOwnPtr<LinkHighlightImpl> LinkHighlightImpl::create(Node* node, WebViewImpl* owningWebViewImpl)
 {
     return adoptPtr(new LinkHighlightImpl(node, owningWebViewImpl));
 }
 
 LinkHighlightImpl::LinkHighlightImpl(Node* node, WebViewImpl* owningWebViewImpl)
     : m_node(node)
     , m_owningWebViewImpl(owningWebViewImpl)
     , m_currentGraphicsLayer(0)
+    , m_isScrollingGraphicsLayer(false)
     , m_geometryNeedsUpdate(false)
     , m_isAnimating(false)
     , m_startTime(monotonicallyIncreasingTime())
 {
     DCHECK(m_node);
     DCHECK(owningWebViewImpl);
     WebCompositorSupport* compositorSupport = Platform::current()->compositorSupport();
     DCHECK(compositorSupport);
     m_contentLayer = adoptPtr(compositorSupport->createContentLayer(this));
     m_clipLayer = adoptPtr(compositorSupport->createLayer());
@@ skipping 36 matching lines @@
 }
 
 void LinkHighlightImpl::releaseResources()
 {
     m_node.clear();
 }
 
 void LinkHighlightImpl::attachLinkHighlightToCompositingLayer(const LayoutBoxModelObject& paintInvalidationContainer)
 {
     GraphicsLayer* newGraphicsLayer = paintInvalidationContainer.layer()->graphicsLayerBacking();
+    m_isScrollingGraphicsLayer = false;
     // FIXME: There should always be a GraphicsLayer. See crbug.com/431961.
-    if (newGraphicsLayer && !newGraphicsLayer->drawsContent())
+    if (paintInvalidationContainer.layer()->needsCompositedScrolling() && m_node->layoutObject() != &paintInvalidationContainer) {
         newGraphicsLayer = paintInvalidationContainer.layer()->graphicsLayerBackingForScrolling();
+        m_isScrollingGraphicsLayer = true;
+    }
     if (!newGraphicsLayer)
         return;
 
     m_clipLayer->setTransform(SkMatrix44(SkMatrix44::kIdentity_Constructor));
 
     if (m_currentGraphicsLayer != newGraphicsLayer) {
         if (m_currentGraphicsLayer)
             clearGraphicsLayerLinkHighlightPointer();
 
         m_currentGraphicsLayer = newGraphicsLayer;
@@ skipping 72 matching lines @@
 
     // Get quads for node in absolute coordinates.
     Vector<FloatQuad> quads;
     computeQuads(*m_node, quads);
     DCHECK(quads.size());
     Path newPath;
 
     for (size_t quadIndex = 0; quadIndex < quads.size(); ++quadIndex) {
         FloatQuad absoluteQuad = quads[quadIndex];
 
+        // Scrolling content layers have the same offset from layout object as the non-scrolling layers. Thus we need
+        // to adjust for their scroll offset.
+        if (m_isScrollingGraphicsLayer) {
+            DoubleSize adjustedScrollOffset = paintInvalidationContainer.layer()->getScrollableArea()->adjustedScrollOffset();
+            absoluteQuad.move(adjustedScrollOffset.width(), adjustedScrollOffset.height());
+        }
+
         // Transform node quads in target absolute coords to local coordinates in the compositor layer.
         FloatQuad transformedQuad;
         convertTargetSpaceQuadToCompositedLayer(absoluteQuad, m_node->layoutObject(), paintInvalidationContainer, transformedQuad);
 
         // FIXME: for now, we'll only use rounded paths if we have a single node quad. The reason for this is that
         // we may sometimes get a chain of adjacent boxes (e.g. for text nodes) which end up looking like sausage
         // links: these should ideally be merged into a single rect before creating the path, but that's
         // another CL.
         if (quads.size() == 1 && transformedQuad.isRectilinear()
             && !m_owningWebViewImpl->settingsImpl()->mockGestureTapHighlightsEnabled()) {
@@ skipping 145 matching lines @@
 {
     return clipLayer();
 }
 
 CompositorAnimationPlayer* LinkHighlightImpl::compositorPlayer() const
 {
     return m_compositorPlayer.get();
 }
 
 } // namespace blink