Reland of Add StyleDifference::needsVisualRectUpdate

third_party/WebKit/Source/core/style/StyleDifference.h

 // Copyright 2014 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 StyleDifference_h
 #define StyleDifference_h
 
 #include <iosfwd>
 #include "core/CoreExport.h"
 #include "wtf/Allocator.h"
@@ skipping 15 matching lines @@
     // The object needs to issue paint invalidations if it is affected by text
     // decorations or properties dependent on color (e.g., border or outline).
     TextDecorationOrColorChanged = 1 << 6,
     // If you add a value here, be sure to update kPropertyDifferenceCount.
   };
 
   StyleDifference()
       : m_paintInvalidationType(NoPaintInvalidation),
         m_layoutType(NoLayout),
         m_recomputeOverflow(false),
+        m_visualRectUpdate(false),
         m_propertySpecificDifferences(0),
         m_scrollAnchorDisablingPropertyChanged(false) {}
 
   bool hasDifference() const {
-    bool result = m_paintInvalidationType || m_layoutType ||
-                  m_propertySpecificDifferences;
-    // m_recomputeOverflow, m_scrollAnchorDisablingPropertyChanged and
-    // are never set without other flags set.
-    DCHECK(result ||
-           (!m_recomputeOverflow && !m_scrollAnchorDisablingPropertyChanged));
-    return result;
+    return m_paintInvalidationType || m_layoutType ||
+           m_propertySpecificDifferences || m_recomputeOverflow ||
+           m_visualRectUpdate || m_scrollAnchorDisablingPropertyChanged;
   }
 
   bool hasAtMostPropertySpecificDifferences(
       unsigned propertyDifferences) const {
     return !m_paintInvalidationType && !m_layoutType &&
            !(m_propertySpecificDifferences & ~propertyDifferences);
   }
 
   bool needsFullPaintInvalidation() const {
     return m_paintInvalidationType != NoPaintInvalidation;
@@ skipping 27 matching lines @@
     DCHECK(!needsFullLayout());
     m_layoutType = PositionedMovement;
   }
 
   bool needsFullLayout() const { return m_layoutType == FullLayout; }
   void setNeedsFullLayout() { m_layoutType = FullLayout; }
 
   bool needsRecomputeOverflow() const { return m_recomputeOverflow; }
   void setNeedsRecomputeOverflow() { m_recomputeOverflow = true; }
 
+  bool needsVisualRectUpdate() const { return m_visualRectUpdate; }
+  void setNeedsVisualRectUpdate() { m_visualRectUpdate = true; }
+
   bool transformChanged() const {
     return m_propertySpecificDifferences & TransformChanged;
   }
   void setTransformChanged() {
     m_propertySpecificDifferences |= TransformChanged;
   }
 
   bool opacityChanged() const {
     return m_propertySpecificDifferences & OpacityChanged;
   }
@@ skipping 44 matching lines @@
   enum PaintInvalidationType {
     NoPaintInvalidation,
     PaintInvalidationObject,
     PaintInvalidationSubtree,
   };
   unsigned m_paintInvalidationType : 2;
 
   enum LayoutType { NoLayout = 0, PositionedMovement, FullLayout };
   unsigned m_layoutType : 2;
   unsigned m_recomputeOverflow : 1;
+  unsigned m_visualRectUpdate : 1;
   unsigned m_propertySpecificDifferences : kPropertyDifferenceCount;
   unsigned m_scrollAnchorDisablingPropertyChanged : 1;
 };
 
 CORE_EXPORT std::ostream& operator<<(std::ostream&, const StyleDifference&);
 
 }  // namespace blink
 
 #endif  // StyleDifference_h