Divorce PaintInvalidationState from LayoutState

Source/core/rendering/PaintInvalidationState.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 PaintInvalidationState_h
+#define PaintInvalidationState_h
+
+#include "platform/geometry/LayoutRect.h"
+#include "wtf/Noncopyable.h"
+
+namespace WebCore {
+
+class RenderBox;
+class RenderInline;
+class RenderLayerModelObject;
+class RenderObject;
+class RenderSVGModelObject;
+
+class PaintInvalidationState {
+    WTF_MAKE_NONCOPYABLE(PaintInvalidationState);
+public:
+    PaintInvalidationState(const PaintInvalidationState& next, RenderInline& renderer, const RenderLayerModelObject& paintInvalidationContainer);
+    PaintInvalidationState(const PaintInvalidationState& next, RenderBox& renderer, const RenderLayerModelObject& paintInvalidationContainer);
+    PaintInvalidationState(const PaintInvalidationState& next, RenderSVGModelObject& renderer, const RenderLayerModelObject& paintInvalidationContainer);
+
+    explicit PaintInvalidationState(RenderObject&);
+
+    const LayoutRect& clipRect() const { return m_clipRect; }
+    const LayoutSize& paintOffset() const { return m_paintOffset; }
+
+    bool cachedOffsetsEnabled() const { return m_cachedOffsetsEnabled; }
+    bool isClipped() const { return m_clipped; }
+
+    const RenderLayerModelObject& paintInvalidationContainer() const { return m_paintInvalidationContainer; }
+    RenderObject& renderer() const { return m_renderer; }
+
+    bool canMapToContainer(const RenderLayerModelObject* container) const
+    {
+        return m_cachedOffsetsEnabled && container == &m_paintInvalidationContainer;
+    }
+private:
+    void applyClipIfNeeded(const RenderObject&);
+
+    friend class ForceHorriblySlowRectMapping;
+
+    bool m_clipped;
+    mutable bool m_cachedOffsetsEnabled;

[Julien - ping for review, 2014/07/07 22:09:59]

Does this field have to be mutable?

+
+    LayoutRect m_clipRect;
+
+    // x/y offset from paint invalidation container. Includes relative positioning and scroll offsets.
+    LayoutSize m_paintOffset;
+
+    const RenderLayerModelObject& m_paintInvalidationContainer;
+
+    RenderObject& m_renderer;
+};
+
+} // namespace WebCore
+
+#endif // PaintInvalidationState_h