Force compositing inputs to be clean for getBoundingClientRect

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 808 matching lines @@
 
   clampScrollOffsetAfterOverflowChange();
 
   if (!scrollbarsAreFrozen) {
     updateScrollableAreaSet(hasScrollableHorizontalOverflow() ||
                             hasScrollableVerticalOverflow());
   }
 
   DisableCompositingQueryAsserts disabler;
   positionOverflowControls();
+
+  // Layout of a scrollable area, or any of its descendants (sticky or
+  // otherwise), invalidates the cached sticky constraints.
+  invalidateAllStickyConstraints();
 }
 
 void PaintLayerScrollableArea::clampScrollOffsetAfterOverflowChange() {
   // If a vertical scrollbar was removed, the min/max scroll offsets may have
   // changed, so the scroll offsets needs to be clamped.  If the scroll offset
   // did not change, but the scroll origin *did* change, we still need to notify
   // the scrollbars to update their dimensions.
 
   if (DelayScrollOffsetClampScope::clampingIsDelayed()) {
     DelayScrollOffsetClampScope::setNeedsClamp(this);
@@ skipping 1278 matching lines @@
 
 void PaintLayerScrollableArea::DelayScrollOffsetClampScope::
     clampScrollableAreas() {
   for (auto& scrollableArea : *s_needsClamp)
     scrollableArea->clampScrollOffsetAfterOverflowChange();
   delete s_needsClamp;
   s_needsClamp = nullptr;
 }
 
 }  // namespace blink