Refactor ScrollableArea::setScrollPosition.

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 f9e9c1e7acdc96ee82cd141590d4d6d39b267ada..aaaee8c578b7bdbb664dd5c4d21e66aa6d12ab25 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
@@ -1087,8 +1087,7 @@ void CompositedLayerMapping::updateOverflowControlsHostLayerGeometry(
       hostLayerPosition = LayoutPoint(transformState.lastPlanarPoint());
       if (PaintLayerScrollableArea* scrollableArea =
               compositingStackingContext->getScrollableArea())
-        hostLayerPosition.move(
-            LayoutSize(scrollableArea->adjustedScrollOffset()));
+        hostLayerPosition.move(LayoutSize(scrollableArea->offsetFromOrigin()));
       hostLayerPosition.move(-stackingOffsetFromLayoutObject);
     }
   } else {
@@ -1195,8 +1194,8 @@ void CompositedLayerMapping::updateScrollingLayerGeometry(
   LayoutBox* layoutBox = toLayoutBox(layoutObject());
   IntRect overflowClipRect =
       enclosingIntRect(layoutBox->overflowClipRect(LayoutPoint()));
-  DoubleSize adjustedScrollOffset =
-      m_owningLayer.getScrollableArea()->adjustedScrollOffset();
+  DoubleSize scrollOffsetFromOrigin =
+      m_owningLayer.getScrollableArea()->offsetFromOrigin();
   m_scrollingLayer->setPosition(FloatPoint(
       overflowClipRect.location() - localCompositingBounds.location() +
       roundedIntSize(m_owningLayer.subpixelAccumulation())));
@@ -1223,8 +1222,8 @@ void CompositedLayerMapping::updateScrollingLayerGeometry(
     m_scrollingContentsLayer->setNeedsDisplay();
 
   DoubleSize scrollingContentsOffset(
-      overflowClipRect.location().x() - adjustedScrollOffset.width(),
-      overflowClipRect.location().y() - adjustedScrollOffset.height());
+      overflowClipRect.location().x() - scrollOffsetFromOrigin.width(),
+      overflowClipRect.location().y() - scrollOffsetFromOrigin.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 ||
@@ -1234,7 +1233,7 @@ void CompositedLayerMapping::updateScrollingLayerGeometry(
     m_scrollingContentsLayer->setPosition(
         coordinatorHandlesOffset
             ? FloatPoint()
-            : FloatPoint(-toFloatSize(adjustedScrollOffset)));
+            : FloatPoint(-toFloatSize(scrollOffsetFromOrigin)));
   }
   m_scrollingContentsOffset = scrollingContentsOffset;
 
@@ -2824,8 +2823,8 @@ void CompositedLayerMapping::adjustForCompositedScrolling(
       if (scrollableArea->usesCompositedScrolling()) {
         // Note: this is just the scroll offset, *not* the "adjusted scroll offset". Scroll offset

[bokan, 2016/10/01 20:32:47]

This comment needs to be updated

[szager1, 2016/10/02 19:35:28]

Done.

         // does not include the origin adjustment. That is instead baked already into offsetFromLayoutObject.
-        DoubleSize scrollOffset = scrollableArea->scrollOffset();
-        offset.expand(-scrollOffset.width(), -scrollOffset.height());
+        IntPoint scrollPosition = scrollableArea->scrollPosition();
+        offset.expand(-scrollPosition.x(), -scrollPosition.y());
       }
     }
   }