Invalidate paint properties on paint offset changes

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@gmail.com>
@@ skipping 424 matching lines @@
     if (!frameView->invalidateViewportConstrainedObjects())
       requiresPaintInvalidation = true;
   }
 
   // Just schedule a full paint invalidation of our object.
   // FIXME: This invalidation will be unnecessary in slimming paint phase 2.
   if (requiresPaintInvalidation) {
     box().setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants();
   }
 
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled()) {
+    // The scrollOffsetTranslation paint property depends on the scroll offset.
+    // (see: PaintPropertyTreeBuilder.updateProperties(FrameView&,...) and
+    // PaintPropertyTreeBuilder.updateScrollAndScrollTranslation).
+    if (!RuntimeEnabledFeatures::rootLayerScrollingEnabled() &&
+        layer()->isRootLayer()) {
+      frameView->setNeedsPaintPropertyUpdate();
+    } else {
+      box().setNeedsPaintPropertyUpdate();
+    }
+  }
+
   // Schedule the scroll DOM event.
   if (box().node())
     box().node()->document().enqueueScrollEventForNode(box().node());
 
   if (AXObjectCache* cache = box().document().existingAXObjectCache())
     cache->handleScrollPositionChanged(&box());
   box().view()->clearHitTestCache();
 
   // Inform the FrameLoader of the new scroll position, so it can be restored
   // when navigating back.
@@ skipping 1209 matching lines @@
     isVisibleToHitTest &= owner->layoutObject() &&
                           owner->layoutObject()->style()->visibleToHitTesting();
   }
 
   bool didScrollOverflow = m_scrollsOverflow;
 
   m_scrollsOverflow = hasOverflow && isVisibleToHitTest;
   if (didScrollOverflow == scrollsOverflow())
     return;
 
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled()) {
+    // The scroll and scroll offset properties depend on |scrollsOverflow| (see:
+    // PaintPropertyTreeBuilder::updateScrollAndScrollTranslation).
+    box().setNeedsPaintPropertyUpdate();
+  }
+
   if (m_scrollsOverflow) {
     DCHECK(canHaveOverflowScrollbars(box()));
     frameView->addScrollableArea(this);
   } else {
     frameView->removeScrollableArea(this);
   }
 }
 
 void PaintLayerScrollableArea::updateCompositingLayersAfterScroll() {
   PaintLayerCompositor* compositor = box().view()->compositor();
@@ skipping 332 matching lines @@
 
 void PaintLayerScrollableArea::DelayScrollOffsetClampScope::
     clampScrollableAreas() {
   for (auto& scrollableArea : *s_needsClamp)
     scrollableArea->clampScrollOffsetAfterOverflowChange();
   delete s_needsClamp;
   s_needsClamp = nullptr;
 }
 
 }  // namespace blink