Invalidate subsequence caching & empty paint phases if clips changed.

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

 // Copyright 2015 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 PrePaintTreeWalk_h
 #define PrePaintTreeWalk_h
 
+#include "core/paint/ClipRect.h"
 #include "core/paint/PaintInvalidator.h"
 #include "core/paint/PaintPropertyTreeBuilder.h"
 
 namespace blink {
 
 class FrameView;
 class GeometryMapper;
 class LayoutObject;
 struct PrePaintTreeWalkContext;
 
 // This class walks the whole layout tree, beginning from the root FrameView,
 // across frame boundaries. Helper classes are called for each tree node to
 // perform actual actions.  It expects to be invoked in InPrePaint phase.
 class PrePaintTreeWalk {
  public:
   PrePaintTreeWalk(GeometryMapper& geometryMapper)
-      : m_paintInvalidator(geometryMapper) {}
+      : m_paintInvalidator(geometryMapper), m_geometryMapper(geometryMapper) {}
   void walk(FrameView& rootFrame);
 
  private:
   void walk(FrameView&, const PrePaintTreeWalkContext&);
   void walk(const LayoutObject&, const PrePaintTreeWalkContext&);
 
+  // Invalidates paint-layer painting optimizations, such as
+  // subsequence caching and empty paint phase optimizations,
+  // if clips from the context have changed.
+  void invalidatePaintLayerOptimizationsIfNeeded(
+      const LayoutObject&,
+      const PaintLayer& ancestorTransformedOrRootPaintLayer,
+      PaintPropertyTreeBuilderContext&);
+
+  // Returns the clip applied to children for the given
+  // contaiing block context + effect, in the space of ancestorState adjusted
+  // by ancestorPaintOffset. Sets hasClip to true if a clip was applied.
+  ClipRect clipRectForContext(
+      const PaintPropertyTreeBuilderContext::ContainingBlockContext&,
+      const EffectPaintPropertyNode*,
+      const PropertyTreeState& ancestorState,
+      const LayoutPoint& ancestorPaintOffset,
+      bool& hasClip);
+
   PaintPropertyTreeBuilder m_propertyTreeBuilder;
   PaintInvalidator m_paintInvalidator;
+  GeometryMapper& m_geometryMapper;
 };
 
 }  // namespace blink
 
 #endif  // PrePaintTreeWalk_h