Disable clipping on root scroller's ancestors.

third_party/WebKit/Source/core/paint/PaintLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. 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@web.de>
@@ skipping 567 matching lines @@
     bool needsCompositingInputsUpdate() const
     {
         // While we're updating the compositing inputs, these values may differ.
         // We should never be asking for this value when that is the case.
         ASSERT(m_needsDescendantDependentCompositingInputsUpdate == m_needsAncestorDependentCompositingInputsUpdate);
         return m_needsDescendantDependentCompositingInputsUpdate;
     }
 
     void updateAncestorOverflowLayer(const PaintLayer* ancestorOverflowLayer) { m_ancestorOverflowLayer = ancestorOverflowLayer; }
     void updateAncestorDependentCompositingInputs(const AncestorDependentCompositingInputs&, const RareAncestorDependentCompositingInputs&, bool hasAncestorWithClipPath);
-    void updateDescendantDependentCompositingInputs(bool hasDescendantWithClipPath, bool hasNonIsolatedDescendantWithBlendMode);
+    void updateDescendantDependentCompositingInputs(bool hasDescendantWithClipPath, bool hasNonIsolatedDescendantWithBlendMode, bool hasRootScrollerAsDescendant);
     void didUpdateCompositingInputs();
 
     IntRect clippedAbsoluteBoundingBox() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_ancestorDependentCompositingInputs.clippedAbsoluteBoundingBox; }
     const PaintLayer* opacityAncestor() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_rareAncestorDependentCompositingInputs ? m_rareAncestorDependentCompositingInputs->opacityAncestor : nullptr; }
     const PaintLayer* transformAncestor() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_rareAncestorDependentCompositingInputs ? m_rareAncestorDependentCompositingInputs->transformAncestor : nullptr; }
     const PaintLayer* filterAncestor() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_rareAncestorDependentCompositingInputs ? m_rareAncestorDependentCompositingInputs->filterAncestor : nullptr; }
     const LayoutObject* clippingContainer() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_ancestorDependentCompositingInputs.clippingContainer; }
     const PaintLayer* ancestorOverflowLayer() const { return m_ancestorOverflowLayer; }
     const PaintLayer* ancestorScrollingLayer() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_rareAncestorDependentCompositingInputs ? m_rareAncestorDependentCompositingInputs->ancestorScrollingLayer : nullptr; }
     const PaintLayer* nearestFixedPositionLayer() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_rareAncestorDependentCompositingInputs ? m_rareAncestorDependentCompositingInputs->nearestFixedPositionLayer : nullptr; }
     const PaintLayer* scrollParent() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_rareAncestorDependentCompositingInputs ? m_rareAncestorDependentCompositingInputs->scrollParent : nullptr; }
     const PaintLayer* clipParent() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_rareAncestorDependentCompositingInputs ? m_rareAncestorDependentCompositingInputs->clipParent : nullptr; }
     bool hasAncestorWithClipPath() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_hasAncestorWithClipPath; }
     bool hasDescendantWithClipPath() const { ASSERT(!m_needsDescendantDependentCompositingInputsUpdate); return m_hasDescendantWithClipPath; }
     bool hasNonIsolatedDescendantWithBlendMode() const;
 
+    bool hasRootScrollerAsDescendant() const { ASSERT(!m_needsDescendantDependentCompositingInputsUpdate); return m_hasRootScrollerAsDescendant; }
+
     bool lostGroupedMapping() const { ASSERT(isAllowedToQueryCompositingState()); return m_lostGroupedMapping; }
     void setLostGroupedMapping(bool b) { m_lostGroupedMapping = b; }
 
     CompositingReasons getCompositingReasons() const { ASSERT(isAllowedToQueryCompositingState()); return m_rareData ? m_rareData->compositingReasons : CompositingReasonNone; }
     void setCompositingReasons(CompositingReasons, CompositingReasons mask = CompositingReasonAll);
 
     SquashingDisallowedReasons getSquashingDisallowedReasons() const { ASSERT(isAllowedToQueryCompositingState()); return m_rareData ? m_rareData->squashingDisallowedReasons : SquashingDisallowedReasonsNone; }
     void setSquashingDisallowedReasons(SquashingDisallowedReasons);
 
     bool hasCompositingDescendant() const { ASSERT(isAllowedToQueryCompositingState()); return m_hasCompositingDescendant; }
@@ skipping 236 matching lines @@
     unsigned m_previousPaintResult : 1; // PaintLayerPainter::PaintResult
 
     unsigned m_needsPaintPhaseDescendantOutlines : 1;
     unsigned m_needsPaintPhaseFloat : 1;
     unsigned m_needsPaintPhaseDescendantBlockBackgrounds : 1;
 
     // These bitfields are part of ancestor/descendant dependent compositing inputs.
     unsigned m_hasDescendantWithClipPath : 1;
     unsigned m_hasNonIsolatedDescendantWithBlendMode : 1;
     unsigned m_hasAncestorWithClipPath : 1;
+    unsigned m_hasRootScrollerAsDescendant : 1;
 
     LayoutBoxModelObject* m_layoutObject;
 
     PaintLayer* m_parent;
     PaintLayer* m_previous;
     PaintLayer* m_next;
     PaintLayer* m_first;
     PaintLayer* m_last;
 
     // Our (x,y) coordinates are in our parent layer's coordinate space.
@@ skipping 30 matching lines @@
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const blink::PaintLayer*);
 void showLayerTree(const blink::LayoutObject*);
 #endif
 
 #endif // Layer_h