Remove isUnclippedDescendant.

Source/core/rendering/RenderLayer.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 382 matching lines @@
     class AncestorDependentCompositingInputs {
     public:
         AncestorDependentCompositingInputs()
             : opacityAncestor(0)
             , transformAncestor(0)
             , filterAncestor(0)
             , clippingContainer(0)
             , ancestorScrollingLayer(0)
             , scrollParent(0)
             , clipParent(0)
-            , isUnclippedDescendant(false)
             , hasAncestorWithClipPath(false)
         { }
 
         IntRect clippedAbsoluteBoundingBox;
         const RenderLayer* opacityAncestor;
         const RenderLayer* transformAncestor;
         const RenderLayer* filterAncestor;
         const RenderObject* clippingContainer;
         const RenderLayer* ancestorScrollingLayer;
 
         // A scroll parent is a compositor concept. It's only needed in blink
         // because we need to use it as a promotion trigger. A layer has a
         // scroll parent if neither its compositor scrolling ancestor, nor any
         // other layer scrolled by this ancestor, is a stacking ancestor of this
         // layer. Layers with scroll parents must be scrolled with the main
         // scrolling layer by the compositor.
         const RenderLayer* scrollParent;
 
         // A clip parent is another compositor concept that has leaked into
         // blink so that it may be used as a promotion trigger. Layers with clip
         // parents escape the clip of a stacking tree ancestor. The compositor
         // needs to know about clip parents in order to circumvent its normal
         // clipping logic.
         const RenderLayer* clipParent;
 
-        // The "is unclipped descendant" concept is now only being used for one
-        // purpose: when traversing the RenderLayers in stacking order, we check
-        // if we scroll wrt to these unclipped descendants. We do this to
-        // proactively promote in the same way that we do for animated layers.
-        // Since we have no idea where scrolled content will scroll to, we just
-        // assume that it can overlap the unclipped thing at some point, so we
-        // promote. But this is unfortunate. We should be able to inflate the
-        // bounds of scrolling content for overlap the same way we're doing for
-        // animation and only promote what's necessary. Once we're doing that,
-        // we won't need to use the "unclipped" concept for promotion any
-        // longer.
-        unsigned isUnclippedDescendant : 1;
         unsigned hasAncestorWithClipPath : 1;
     };
 
     class DescendantDependentCompositingInputs {
     public:
         DescendantDependentCompositingInputs()
             : hasDescendantWithClipPath(false)
             , hasNonIsolatedDescendantWithBlendMode(false)
         { }
 
@@ skipping 19 matching lines @@
     const DescendantDependentCompositingInputs& descendantDependentCompositingInputs() const { ASSERT(!m_needsDescendantDependentCompositingInputsUpdate); return m_descendantDependentCompositingInputs; }
 
     IntRect clippedAbsoluteBoundingBox() const { return ancestorDependentCompositingInputs().clippedAbsoluteBoundingBox; }
     const RenderLayer* opacityAncestor() const { return ancestorDependentCompositingInputs().opacityAncestor; }
     const RenderLayer* transformAncestor() const { return ancestorDependentCompositingInputs().transformAncestor; }
     const RenderLayer* filterAncestor() const { return ancestorDependentCompositingInputs().filterAncestor; }
     const RenderObject* clippingContainer() const { return ancestorDependentCompositingInputs().clippingContainer; }
     const RenderLayer* ancestorScrollingLayer() const { return ancestorDependentCompositingInputs().ancestorScrollingLayer; }
     RenderLayer* scrollParent() const { return const_cast<RenderLayer*>(ancestorDependentCompositingInputs().scrollParent); }
     RenderLayer* clipParent() const { return const_cast<RenderLayer*>(ancestorDependentCompositingInputs().clipParent); }
-    bool isUnclippedDescendant() const { return ancestorDependentCompositingInputs().isUnclippedDescendant; }
     bool hasAncestorWithClipPath() const { return ancestorDependentCompositingInputs().hasAncestorWithClipPath; }
     bool hasDescendantWithClipPath() const { return descendantDependentCompositingInputs().hasDescendantWithClipPath; }
     bool hasNonIsolatedDescendantWithBlendMode() const { return descendantDependentCompositingInputs().hasNonIsolatedDescendantWithBlendMode; }
 
     bool lostGroupedMapping() const { ASSERT(isAllowedToQueryCompositingState()); return m_lostGroupedMapping; }
     void setLostGroupedMapping(bool b) { m_lostGroupedMapping = b; }
 
     CompositingReasons compositingReasons() const { ASSERT(isAllowedToQueryCompositingState()); return m_compositingReasons; }
     void setCompositingReasons(CompositingReasons, CompositingReasons mask = CompositingReasonAll);
 
@@ skipping 217 matching lines @@
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const blink::RenderLayer*);
 void showLayerTree(const blink::RenderObject*);
 #endif
 
 #endif // RenderLayer_h