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

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

Index: third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
index d36b46bdf321ddeb49160399dbc4ad3b18f0d130..94dc9dc1c90eecfb94fc31f9a0c1559b5b33f8b1 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
@@ -1007,14 +1007,14 @@
     DoubleSize scrollingContentsOffset(overflowClipRect.location().x() - adjustedScrollOffset.width(), overflowClipRect.location().y() - adjustedScrollOffset.height());
     // The scroll offset change is compared using floating point so that fractional scroll offset
     // change can be propagated to compositor.
-    if (scrollingContentsOffset != m_scrollingContentsOffset || scrollSize != m_scrollingContentsLayer->size()) {
+    if (scrollingContentsOffset != m_scrollingContentsLayer->offsetDoubleFromLayoutObject() || scrollSize != m_scrollingContentsLayer->size()) {
         bool coordinatorHandlesOffset = compositor()->scrollingLayerDidChange(&m_owningLayer);
         m_scrollingContentsLayer->setPosition(coordinatorHandlesOffset ? FloatPoint() : FloatPoint(-toFloatSize(adjustedScrollOffset)));
     }
-    m_scrollingContentsOffset = scrollingContentsOffset;
 
     m_scrollingContentsLayer->setSize(FloatSize(scrollSize));
-    m_scrollingContentsLayer->setOffsetDoubleFromLayoutObject(toIntSize(overflowClipRect.location()), GraphicsLayer::DontSetNeedsDisplay);
+    // FIXME: The paint offset and the scroll offset should really be separate concepts.
+    m_scrollingContentsLayer->setOffsetDoubleFromLayoutObject(scrollingContentsOffset, GraphicsLayer::DontSetNeedsDisplay);
 
     if (m_foregroundLayer) {
         if (m_foregroundLayer->size() != m_scrollingContentsLayer->size())
@@ -1416,8 +1416,7 @@
     ApplyToMaskLayers = (1 << 4),
     ApplyToContentLayers = (1 << 5),
     ApplyToChildContainingLayers = (1 << 6), // layers between m_graphicsLayer and children
-    ApplyToScrollingContentLayers = (1 << 7),
-    ApplyToAllGraphicsLayers = (ApplyToSquashingLayer | ApplyToScrollbarLayers | ApplyToBackgroundLayer | ApplyToMaskLayers | ApplyToLayersAffectedByPreserve3D | ApplyToContentLayers | ApplyToScrollingContentLayers)
+    ApplyToAllGraphicsLayers = (ApplyToSquashingLayer | ApplyToScrollbarLayers | ApplyToBackgroundLayer | ApplyToMaskLayers | ApplyToLayersAffectedByPreserve3D | ApplyToContentLayers)
 };
 typedef unsigned ApplyToGraphicsLayersMode;
 
@@ -1434,9 +1433,9 @@
         f(mapping->clippingLayer());
     if (((mode & ApplyToLayersAffectedByPreserve3D) || (mode & ApplyToChildContainingLayers)) && mapping->scrollingLayer())
         f(mapping->scrollingLayer());
-    if (((mode & ApplyToLayersAffectedByPreserve3D) || (mode & ApplyToContentLayers) || (mode & ApplyToChildContainingLayers) || (mode & ApplyToScrollingContentLayers)) && mapping->scrollingContentsLayer())
+    if (((mode & ApplyToLayersAffectedByPreserve3D) || (mode & ApplyToContentLayers) || (mode & ApplyToChildContainingLayers)) && mapping->scrollingContentsLayer())
         f(mapping->scrollingContentsLayer());
-    if (((mode & ApplyToLayersAffectedByPreserve3D) || (mode & ApplyToContentLayers) || (mode & ApplyToScrollingContentLayers)) && mapping->foregroundLayer())
+    if (((mode & ApplyToLayersAffectedByPreserve3D) || (mode & ApplyToContentLayers)) && mapping->foregroundLayer())
         f(mapping->foregroundLayer());
 
     if ((mode & ApplyToChildContainingLayers) && mapping->childTransformLayer())
@@ -2108,26 +2107,6 @@
         client
     };
     ApplyToGraphicsLayers(this, functor, ApplyToContentLayers);
-}
-
-void CompositedLayerMapping::setScrollingContentsNeedDisplayInRect(const LayoutRect& r, PaintInvalidationReason invalidationReason, const DisplayItemClient& client)
-{
-    // TODO(wangxianzhu): Enable the following assert after paint invalidation for spv2 is ready.
-    // ASSERT(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
-
-    SetContentsNeedsDisplayInRectFunctor functor = {
-        enclosingIntRect(LayoutRect(r.location() + m_owningLayer.subpixelAccumulation(), r.size())),
-        invalidationReason,
-        client
-    };
-    ApplyToGraphicsLayers(this, functor, ApplyToScrollingContentLayers);
-}
-
-void CompositedLayerMapping::scrollingDisplayItemClientWasInvalidated(const DisplayItemClient& displayItemClient, PaintInvalidationReason paintInvalidationReason)
-{
-    ApplyToGraphicsLayers(this, [&displayItemClient, paintInvalidationReason](GraphicsLayer* layer) {
-        layer->displayItemClientWasInvalidated(displayItemClient, paintInvalidationReason);
-    }, ApplyToScrollingContentLayers);
 }
 
 void CompositedLayerMapping::displayItemClientWasInvalidated(const DisplayItemClient& displayItemClient, PaintInvalidationReason paintInvalidationReason)
@@ -2261,7 +2240,6 @@
         ASSERT(graphicsLayer == m_graphicsLayer || graphicsLayer == m_scrollingContentsLayer);
         anchorLayoutObject = m_owningLayer.layoutObject();
         offsetFromAnchorLayoutObject = graphicsLayer->offsetFromLayoutObject();
-        adjustForCompositedScrolling(graphicsLayer, offsetFromAnchorLayoutObject);
     }
 
     // Start with the bounds of the graphics layer in the space of the anchor LayoutObject.
@@ -2360,14 +2338,6 @@
 bool CompositedLayerMapping::needsRepaint(const GraphicsLayer& graphicsLayer) const
 {
     return isScrollableAreaLayer(&graphicsLayer) ? true : m_owningLayer.needsRepaint();
-}
-
-void CompositedLayerMapping::adjustForCompositedScrolling(const GraphicsLayer* graphicsLayer, IntSize& offset) const
-{
-    if (graphicsLayer == m_scrollingContentsLayer.get() || graphicsLayer == m_foregroundLayer.get()) {
-        DoubleSize adjustedScrollOffset = m_owningLayer.getScrollableArea()->adjustedScrollOffset();
-        offset.expand(-adjustedScrollOffset.width(), -adjustedScrollOffset.height());
-    }
 }
 
 void CompositedLayerMapping::paintContents(const GraphicsLayer* graphicsLayer, GraphicsContext& context,
@@ -2416,7 +2386,6 @@
         paintInfo.paintLayer = &m_owningLayer;
         paintInfo.compositedBounds = compositedBounds();
         paintInfo.offsetFromLayoutObject = graphicsLayer->offsetFromLayoutObject();
-        adjustForCompositedScrolling(graphicsLayer, paintInfo.offsetFromLayoutObject);
 
         // We have to use the same root as for hit testing, because both methods can compute and cache clipRects.
         doPaintTask(paintInfo, *graphicsLayer, paintLayerFlags, context, interestRect);