Tweak priorities of paint invalidation reasons

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

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1102 matching lines @@
     // Invalidate the paint of a specific subrectangle within a given object. The rect is in the object's coordinate space.
     void invalidatePaintRectangle(const LayoutRect&) const;
 
     // Walk the tree after layout issuing paint invalidations for layoutObjects that have changed or moved, updating bounds that have changed, and clearing paint invalidation state.
     virtual void invalidateTreeIfNeeded(const PaintInvalidationState&);
 
     void invalidatePaintIncludingNonCompositingDescendants();
     void invalidatePaintIncludingNonSelfPaintingLayerDescendants(const LayoutBoxModelObject& paintInvalidationContainer);
     void setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants();
 
-    // Returns true if the object will not generate any effective painted output.
+    // Returns true if the object itself will not generate any effective painted output no matter what
+    // size the object is. For example, this function can return false for an object whose size is
+    // currently 0x0 but would have effective painted output if it was set a non-empty size.
     // It's used to skip unforced paint invalidation (which is when shouldDoFullPaintInvalidation
     // is false, but mayNeedPaintInvalidation or childShouldCheckForPaintInvalidation is true) to
     // avoid unnecessary paint invalidations of empty areas covered by such objects.
-    virtual bool paintedOutputOfObjectHasNoEffect() const { return false; }
+    virtual bool paintedOutputOfObjectHasNoEffectRegardlessOfSize() const { return false; }
 
     // Returns the rect that should have paint invalidated whenever this object changes. The rect is in the view's
     // coordinate space. This method deals with outlines and overflow.
     virtual LayoutRect absoluteClippedOverflowRect() const;
 
     // Returns the rect that should have paint invalidated whenever this object changes. The rect is in the object's
     // local coordinate space. This is for non-SVG objects and LayoutSVGRoot only. SVG objects (except LayoutSVGRoot)
     // should use paintInvalidationRectInLocalSVGCoordinates() and map with SVG transforms instead.
     virtual LayoutRect localOverflowRectForPaintInvalidation() const;
 
@@ skipping 1019 matching lines @@
 void showTree(const blink::LayoutObject*);
 void showLineTree(const blink::LayoutObject*);
 void showLayoutTree(const blink::LayoutObject* object1);
 // We don't make object2 an optional parameter so that showLayoutTree
 // can be called from gdb easily.
 void showLayoutTree(const blink::LayoutObject* object1, const blink::LayoutObject* object2);
 
 #endif
 
 #endif // LayoutObject_h