Divorce PaintInvalidationState from LayoutState

Source/core/rendering/InvalidationTreeWalkState.h

Index: Source/core/rendering/InvalidationTreeWalkState.h
diff --git a/Source/core/rendering/InvalidationTreeWalkState.h b/Source/core/rendering/InvalidationTreeWalkState.h
new file mode 100644
index 0000000000000000000000000000000000000000..f85c3cbba5375f435854ac81cd667869d68fe264
--- /dev/null
+++ b/Source/core/rendering/InvalidationTreeWalkState.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2014 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef InvalidationTreeWalkState_h
+#define InvalidationTreeWalkState_h
+
+#include "platform/geometry/LayoutRect.h"
+#include "wtf/Noncopyable.h"
+
+namespace WebCore {
+
+class RenderBox;
+class RenderInline;
+class RenderLayerModelObject;
+class RenderObject;
+class RenderSVGModelObject;
+
+class InvalidationTreeWalkState {
+    WTF_MAKE_NONCOPYABLE(InvalidationTreeWalkState);
+public:
+    InvalidationTreeWalkState(const InvalidationTreeWalkState& next, RenderInline& renderer, const RenderLayerModelObject& paintInvalidationContainer);
+    InvalidationTreeWalkState(const InvalidationTreeWalkState& next, RenderBox& renderer, const RenderLayerModelObject& paintInvalidationContainer);
+    InvalidationTreeWalkState(const InvalidationTreeWalkState& next, RenderSVGModelObject& renderer, const RenderLayerModelObject& paintInvalidationContainer);
+
+    InvalidationTreeWalkState(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;

[Julien - ping for review, 2014/07/02 00:27:28]

Is it common for container != m_paintInvalidationContainer or is it just when
traversing paint container boundaries?

[leviw_travelin_and_unemployed, 2014/07/02 00:41:02]

I'd have to validate.

+    }
+private:
+    void applyClipIfNeeded(const RenderObject&);
+
+    friend class ForceHorriblySlowRectMapping;
+
+    bool m_clipped;
+    mutable bool m_cachedOffsetsEnabled;
+
+    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 // InvalidationTreeWalkState_h