Disable incremental invalidation for SVG

third_party/WebKit/Source/core/layout/svg/LayoutSVGModelObject.cpp

 /*
  * Copyright (c) 2009, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 70 matching lines @@
 {
     quads.append(localToAbsoluteQuad(strokeBoundingBox()));
 }
 
 void LayoutSVGModelObject::willBeDestroyed()
 {
     SVGResourcesCache::clientDestroyed(this);
     LayoutObject::willBeDestroyed();
 }
 
+PaintInvalidationReason LayoutSVGModelObject::getPaintInvalidationReason(const PaintInvalidationState& paintInvalidationState,
+    const LayoutRect& oldBounds, const LayoutPoint& oldLocation, const LayoutRect& newBounds, const LayoutPoint& newLocation) const
+{
+    PaintInvalidationReason invalidationReason = LayoutObject::getPaintInvalidationReason(paintInvalidationState, oldBounds, oldLocation, newBounds, newLocation);
+
+    // Disable incremental invalidation for SVG objects to prevent under-
+    // invalidation. Unlike boxes, it is non-trivial (and rare) for SVG objects
+    // to be able to be incrementally invalidated (e.g., on height changes).
+    if (invalidationReason == PaintInvalidationIncremental)
+        return PaintInvalidationFull;
+
+    return invalidationReason;
+}
+
 void LayoutSVGModelObject::computeLayerHitTestRects(LayerHitTestRects& rects) const
 {
     // Using just the rect for the SVGRoot is good enough for now.
     SVGLayoutSupport::findTreeRootObject(this)->computeLayerHitTestRects(rects);
 }
 
 void LayoutSVGModelObject::addLayerHitTestRects(LayerHitTestRects&, const PaintLayer* currentLayer, const LayoutPoint& layerOffset, const LayoutRect& containerRect) const
 {
     // We don't walk into SVG trees at all - just report their container.
 }
@@ skipping 23 matching lines @@
 }
 
 // The SVG addOutlineRects() method adds rects in local coordinates so the default absoluteElementBoundingBoxRect()
 // returns incorrect values for SVG objects. Overriding this method provides access to the absolute bounds.
 IntRect LayoutSVGModelObject::absoluteElementBoundingBoxRect() const
 {
     return localToAbsoluteQuad(FloatQuad(paintInvalidationRectInLocalSVGCoordinates())).enclosingBoundingBox();
 }
 
 } // namespace blink