Reland of Add StyleDifference::needsVisualRectUpdate

third_party/WebKit/Source/core/style/ComputedStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2011 Adobe Systems Incorporated. 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 538 matching lines @@
       diff.setNeedsFullLayout();
     else
       diff.setNeedsPositionedMovementLayout();
   }
 
   if (diffNeedsPaintInvalidationSubtree(other))
     diff.setNeedsPaintInvalidationSubtree();
   else if (diffNeedsPaintInvalidationObject(other))
     diff.setNeedsPaintInvalidationObject();
 
+  if (diffNeedsVisualRectUpdate(other))
+    diff.setNeedsVisualRectUpdate();
+
   updatePropertySpecificDifferences(other, diff);
 
   // The following condition needs to be at last, because it may depend on
   // conditions in diff computed above.
   if (scrollAnchorDisablingPropertyChanged(other, diff))
     diff.setScrollAnchorDisablingPropertyChanged();
 
   // Cursors are not checked, since they will be set appropriately in response
   // to mouse events, so they don't need to cause any paint invalidation or
   // layout.
@@ skipping 421 matching lines @@
     for (const AtomicString& property :
          *value->customInvalidationProperties()) {
       if (!dataEquivalent(getVariable(property), other.getVariable(property)))
         return true;
     }
   }
 
   return false;
 }
 
+// This doesn't include conditions needing layout or overflow recomputation
+// which implies visual rect update.
+bool ComputedStyle::diffNeedsVisualRectUpdate(
+    const ComputedStyle& other) const {
+  // Visual rect is empty if visibility is hidden.
+  if (visibility() != other.visibility())
+    return true;
+
+  // Need to update visual rect of the resizer.
+  if (resize() != other.resize())
+    return true;
+
+  return false;
+}
+
 void ComputedStyle::updatePropertySpecificDifferences(
     const ComputedStyle& other,
     StyleDifference& diff) const {
   if (m_box->zIndex() != other.m_box->zIndex() ||
       isStackingContext() != other.isStackingContext())
     diff.setZIndexChanged();
 
   if (m_rareNonInheritedData.get() != other.m_rareNonInheritedData.get()) {
     // It's possible for the old and new style transform data to be equivalent
     // while hasTransform() differs, as it checks a number of conditions aside
@@ skipping 1467 matching lines @@
     if (value < 0)
       fvalue -= 0.5f;
     else
       fvalue += 0.5f;
   }
 
   return roundForImpreciseConversion<int>(fvalue / zoomFactor);
 }
 
 }  // namespace blink