Workaround rect-based paint invalidation on ancestor clip change

third_party/WebKit/Source/core/layout/PaintInvalidationState.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PaintInvalidationState_h
 #define PaintInvalidationState_h
 
 #include "platform/geometry/LayoutRect.h"
 #include "platform/transforms/AffineTransform.h"
 #include "wtf/Allocator.h"
@@ skipping 21 matching lines @@
     const LayoutRect& clipRect() const { return m_clipRect; }
     const LayoutSize& paintOffset() const { return m_paintOffset; }
     const AffineTransform& svgTransform() const { ASSERT(m_svgTransform); return *m_svgTransform; }
 
     bool cachedOffsetsEnabled() const { return m_cachedOffsetsEnabled; }
     bool isClipped() const { return m_clipped; }
 
     bool forcedSubtreeInvalidationWithinContainer() const { return m_forcedSubtreeInvalidationWithinContainer; }
     void setForceSubtreeInvalidationWithinContainer() { m_forcedSubtreeInvalidationWithinContainer = true; }
 
+    bool forcedSubtreeInvalidationRectUpdateWithinContainer() const { return m_forcedSubtreeInvalidationRectUpdateWithinContainer; }
+    void setForceSubtreeInvalidationRectUpdateWithinContainer() { m_forcedSubtreeInvalidationRectUpdateWithinContainer = true; }
+
     const LayoutBoxModelObject& paintInvalidationContainer() const { return m_paintInvalidationContainer; }
 
     bool canMapToContainer(const LayoutBoxModelObject* container) const
     {
         return m_cachedOffsetsEnabled && container == &m_paintInvalidationContainer;
     }
 
     // Records |obj| as needing paint invalidation on the next frame. See the definition of PaintInvalidationDelayedFull for more details.
     void pushDelayedPaintInvalidationTarget(LayoutObject& obj) { m_pendingDelayedPaintInvalidations.append(&obj); }
     Vector<LayoutObject*>& pendingDelayedPaintInvalidationTargets() { return m_pendingDelayedPaintInvalidations; }
 
 private:
     PaintInvalidationState(const LayoutView&, Vector<LayoutObject*>& pendingDelayedPaintInvalidations, PaintInvalidationState* ownerPaintInvalidationState);
 
     void applyClipIfNeeded(const LayoutObject&);
     void addClipRectRelativeToPaintOffset(const LayoutSize& clipSize);
 
     friend class ForceHorriblySlowRectMapping;
 
     bool m_clipped;
     mutable bool m_cachedOffsetsEnabled;
     bool m_forcedSubtreeInvalidationWithinContainer;
+    bool m_forcedSubtreeInvalidationRectUpdateWithinContainer;
 
     LayoutRect m_clipRect;
 
     // x/y offset from paint invalidation container. Includes relative positioning and scroll offsets.
     LayoutSize m_paintOffset;
 
     const LayoutBoxModelObject& m_paintInvalidationContainer;
 
     // Transform from the initial viewport coordinate system of an outermost
     // SVG root to the userspace _before_ the relevant element. Combining this
     // with |m_paintOffset| yields the "final" offset.
     OwnPtr<AffineTransform> m_svgTransform;
 
     Vector<LayoutObject*>& m_pendingDelayedPaintInvalidations;
 };
 
 } // namespace blink
 
 #endif // PaintInvalidationState_h