Add default constructor and operator==/!= for CullRect

third_party/WebKit/Source/platform/graphics/paint/CullRect.h

 // Copyright 2015 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 CullRect_h
 #define CullRect_h
 
 #include "platform/geometry/IntRect.h"
 #include "platform/transforms/AffineTransform.h"
 #include "wtf/Allocator.h"
 #include "wtf/HashMap.h"
 #include "wtf/ListHashSet.h"
-#include "wtf/text/WTFString.h"
 
 #include <limits>
 
 namespace blink {
 
 class FloatRect;
 class LayoutRect;
 class LayoutUnit;
 
 class PLATFORM_EXPORT CullRect {
   DISALLOW_NEW();
 
  public:
+  CullRect() {}
   explicit CullRect(const IntRect& rect) : m_rect(rect) {}
   CullRect(const CullRect&, const IntPoint& offset);
   CullRect(const CullRect&, const IntSize& offset);
 
   bool intersectsCullRect(const AffineTransform&,
                           const FloatRect& boundingBox) const;
   void updateCullRect(const AffineTransform& localToParentTransform);
   bool intersectsCullRect(const IntRect&) const;
   bool intersectsCullRect(const LayoutRect&) const;
   bool intersectsHorizontalRange(LayoutUnit lo, LayoutUnit hi) const;
   bool intersectsVerticalRange(LayoutUnit lo, LayoutUnit hi) const;
 
-  String toString() const { return m_rect.toString(); }

[chrishtr, 2016/11/11 19:02:16]

Why remove this?

[Xianzhu, 2016/11/11 19:13:25]

Sorry, this is a mistake when cherry-picking this file from the big change
without rebasing that branch to ToT. Reverted.

-
  private:
   IntRect m_rect;
 
+  friend bool operator==(const CullRect&, const CullRect&);
+
   // TODO(chrishtr): temporary while we implement CullRect everywhere.
   friend class FramePainter;
   friend class GridPainter;
   friend class SVGInlineTextBoxPainter;
   friend class SVGPaintContext;
   friend class SVGRootInlineBoxPainter;
   friend class SVGShapePainter;
   friend class TableSectionPainter;
   friend class ThemePainterMac;
   friend class WebPluginContainerImpl;
 };
 
+inline bool operator==(const CullRect& a, const CullRect& b) {
+  return a.m_rect == b.m_rect;
+}
+inline bool operator!=(const CullRect& a, const CullRect& b) {
+  return !(a == b);
+}
+
 }  // namespace blink
 
 #endif  // CullRect_h