Don't update descendant visual rects on border radius change

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"
@@ skipping 16 matching lines @@
  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.
   ALWAYS_INLINE void InvalidatePaintLayerOptimizationsIfNeeded(
       const LayoutObject&,
       PrePaintTreeWalkContext&);
 
-  // Returns in |clipRect| the clip applied to children for the given
-  // contaiing block context + effect, in the space of ancestorState adjusted
-  // by ancestorPaintOffset.
-  ALWAYS_INLINE void ComputeClipRectForContext(
+  // Returns the clip applied to children for the given containing block context
+  // + effect, in the space of ancestorState adjusted by ancestorPaintOffset.
+  ALWAYS_INLINE LayoutRect ComputeClipRectForContext(
       const PaintPropertyTreeBuilderContext::ContainingBlockContext&,
       const EffectPaintPropertyNode*,
       const PropertyTreeState& ancestor_state,
-      const LayoutPoint& ancestor_paint_offset,
-      FloatClipRect&);
+      const LayoutPoint& ancestor_paint_offset);
 
   bool ALWAYS_INLINE
   NeedsTreeBuilderContextUpdate(const FrameView&,
                                 const PrePaintTreeWalkContext&);
   bool ALWAYS_INLINE
   NeedsTreeBuilderContextUpdate(const LayoutObject&,
                                 const PrePaintTreeWalkContext&);
 
   PaintPropertyTreeBuilder property_tree_builder_;
   PaintInvalidator paint_invalidator_;
 };
 
 }  // namespace blink
 
 #endif  // PrePaintTreeWalk_h