Paint invalidation of local attachment backgrounds

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

 // Copyright 2016 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 BoxPaintInvalidator_h
 #define BoxPaintInvalidator_h
 
 #include "platform/graphics/PaintInvalidationReason.h"
 #include "wtf/Allocator.h"
 
@@ skipping 10 matching lines @@
  public:
   BoxPaintInvalidator(const LayoutBox& box,
                       const PaintInvalidatorContext& context)
       : m_box(box), m_context(context) {}
 
   static void boxWillBeDestroyed(const LayoutBox&);
 
   PaintInvalidationReason invalidatePaintIfNeeded();
 
  private:
+  bool backgroundGeometryDependsOnLayoutOverflowRect();
+  bool backgroundPaintsOntoScrollingContentsLayer();
+  bool shouldFullyInvalidateBackgroundOnLayoutOverflowChange(const LayoutRect&,

[chrishtr, 2016/11/17 20:42:36]

Document these two arguments

[Xianzhu, 2016/11/17 23:36:41]

Done.

+                                                             const LayoutRect&);
+  void invalidateScrollingContentsBackgroundIfNeeded();
+
   PaintInvalidationReason computePaintInvalidationReason();
 
-  bool incrementallyInvalidatePaint();
+  bool incrementallyInvalidatePaint(PaintInvalidationReason,
+                                    const LayoutRect& oldRect,
+                                    const LayoutRect& newRect);
 
   bool needsToSavePreviousBoxGeometries();
   void savePreviousBoxGeometriesIfNeeded();
-  LayoutSize previousBorderBoxSize(const LayoutSize& previousVisualRectSize);
+  LayoutSize previousBorderBoxSize();
   LayoutRect previousContentBoxRect();
   LayoutRect previousLayoutOverflowRect();
 
   const LayoutBox& m_box;
   const PaintInvalidatorContext& m_context;
 };
 
 }  // namespace blink
 
 #endif