Make PaintLayerClipper objects transient

third_party/WebKit/Source/core/paint/PaintLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 28 matching lines @@
  * deletingthe provisions above and replace them with the notice and
  * other provisions required by the MPL or the GPL, as the case may be.
  * If you do not delete the provisions above, a recipient may use your
  * version of this file under any of the LGPL, the MPL or the GPL.
  */
 
 #ifndef PaintLayer_h
 #define PaintLayer_h
 
 #include "core/CoreExport.h"
+#include "core/layout/ClipRectsCache.h"
 #include "core/layout/LayoutBox.h"
 #include "core/paint/PaintLayerClipper.h"
 #include "core/paint/PaintLayerFilterInfo.h"
 #include "core/paint/PaintLayerFragment.h"
 #include "core/paint/PaintLayerPainter.h"
 #include "core/paint/PaintLayerReflectionInfo.h"
 #include "core/paint/PaintLayerScrollableArea.h"
 #include "core/paint/PaintLayerStackingNode.h"
 #include "core/paint/PaintLayerStackingNodeIterator.h"
 #include "platform/graphics/CompositingReasons.h"
@@ skipping 431 matching lines @@
     bool scrollsWithViewport() const;
     bool scrollsWithRespectTo(const PaintLayer*) const;
 
     void addLayerHitTestRects(LayerHitTestRects&) const;
 
     // Compute rects only for this layer
     void computeSelfHitTestRects(LayerHitTestRects&) const;
 
     // FIXME: This should probably return a ScrollableArea but a lot of internal methods are mistakenly exposed.
     PaintLayerScrollableArea* scrollableArea() const { return m_scrollableArea.get(); }
-    PaintLayerClipper& clipper() { return m_clipper; }
-    const PaintLayerClipper& clipper() const { return m_clipper; }
+
+    PaintLayerClipper clipper() const { return PaintLayerClipper(*this); }
 
     bool scrollsOverflow() const;
 
     CompositingReasons potentialCompositingReasonsFromStyle() const { return m_rareData ? m_rareData->potentialCompositingReasonsFromStyle : CompositingReasonNone; }
     void setPotentialCompositingReasonsFromStyle(CompositingReasons reasons)
     {
         ASSERT(reasons == (reasons & CompositingReasonComboAllStyleDeterminedReasons));
         if (m_rareData || reasons != CompositingReasonNone)
             ensureRareData().potentialCompositingReasonsFromStyle = reasons;
     }
@@ skipping 131 matching lines @@
     void clearNeedsRepaintRecursively();
 
     // These previousXXX() functions are for subsequence caching. They save the painting status of the layer
     // during the previous painting with subsequence. A painting without subsequence [1] doesn't change this status.
     // [1] See shouldCreateSubsequence() in PaintLayerPainter.cpp for the cases we use subsequence when painting a PaintLayer.
 
     IntSize previousScrollOffsetAccumulationForPainting() const { return m_previousScrollOffsetAccumulationForPainting; }
     void setPreviousScrollOffsetAccumulationForPainting(const IntSize& s) { m_previousScrollOffsetAccumulationForPainting = s; }
 
     ClipRects* previousPaintingClipRects() const { return m_previousPaintingClipRects.get(); }
-    void setPreviousPaintingClipRects(ClipRects* clipRects) { m_previousPaintingClipRects = clipRects; }
+    void setPreviousPaintingClipRects(ClipRects& clipRects) { m_previousPaintingClipRects = &clipRects; }
 
     LayoutRect previousPaintDirtyRect() const { return m_previousPaintDirtyRect; }
     void setPreviousPaintDirtyRect(const LayoutRect& rect) { m_previousPaintDirtyRect = rect; }
 
     PaintLayerPainter::PaintResult previousPaintResult() const { return static_cast<PaintLayerPainter::PaintResult>(m_previousPaintResult); }
     void setPreviousPaintResult(PaintLayerPainter::PaintResult result) { m_previousPaintResult = static_cast<unsigned>(result); ASSERT(m_previousPaintResult == static_cast<unsigned>(result)); }
 
     // Used to skip PaintPhaseDescendantOutlinesOnly for layers that have never had descendant outlines.
     // Once it's set we never clear it because it's not easy to track if all outlines have been removed.
     bool needsPaintPhaseDescendantOutlines() const { return m_needsPaintPhaseDescendantOutlines; }
     void setNeedsPaintPhaseDescendantOutlines() { ASSERT(isSelfPaintingLayer()); m_needsPaintPhaseDescendantOutlines = true; }
 
     PaintTiming* paintTiming();
 
+    ClipRectsCache* clipRectsCache() const { return m_clipRectsCache.get(); }
+    ClipRectsCache& ensureClipRectsCache() const
+    {
+        if (!m_clipRectsCache)
+            m_clipRectsCache = adoptPtr(new ClipRectsCache);
+        return *m_clipRectsCache;
+    }
+    void clearClipRectsCache() const { m_clipRectsCache.clear(); }
+
 private:
     // Bounding box in the coordinates of this layer.
     LayoutRect logicalBoundingBox() const;
 
     bool hasOverflowControls() const;
 
     void dirtyAncestorChainHasSelfPaintingLayerDescendantStatus();
 
     // Returns true if the position changed.
     bool updateLayerPosition();
@@ skipping 150 matching lines @@
 
     // Cached normal flow values for absolute positioned elements with static left/top values.
     LayoutUnit m_staticInlinePosition;
     LayoutUnit m_staticBlockPosition;
 
     AncestorDependentCompositingInputs m_ancestorDependentCompositingInputs;
     OwnPtr<RareAncestorDependentCompositingInputs> m_rareAncestorDependentCompositingInputs;
 
     OwnPtrWillBePersistent<PaintLayerScrollableArea> m_scrollableArea;
 
-    PaintLayerClipper m_clipper; // FIXME: Lazily allocate?
+    mutable OwnPtr<ClipRectsCache> m_clipRectsCache;
+
     OwnPtr<PaintLayerStackingNode> m_stackingNode;
 
     IntSize m_previousScrollOffsetAccumulationForPainting;
     RefPtr<ClipRects> m_previousPaintingClipRects;
     LayoutRect m_previousPaintDirtyRect;
 
     OwnPtr<PaintLayerRareData> m_rareData;
 };
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const blink::PaintLayer*);
 void showLayerTree(const blink::LayoutObject*);
 #endif
 
 #endif // Layer_h