Change Widget subclasses to use a CullRect instead of an IntRect for painting.

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 <limits>
+
+namespace blink {
+
+class FloatRect;
+class LayoutBoxModelObject;
+class LayoutInline;
+class LayoutObject;
+class LayoutRect;
+class LayoutUnit;
+class PaintInvalidationState;
+
+class PLATFORM_EXPORT CullRect {
+public:
+    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;
+
+private:
+    IntRect m_rect;
+
+    // TODO(chrishtr): temporary while we implement CullRect everywhere.
+    friend class FramePainter;
+    friend class GridPainter;
+    friend class SVGInlineTextBoxPainter;
+    friend class ScrollbarThemeMacNonOverlayAPI;
+    friend class ReplicaPainter;
+    friend class SVGPaintContext;
+    friend class SVGRootInlineBoxPainter;
+    friend class SVGShapePainter;
+    friend class TableSectionPainter;
+    friend class ThemePainterMac;
+    friend class WebPluginContainerImpl;
+};
+
+} // namespace blink
+
+#endif // CullRect_h