Remove backface visibility

sky/engine/core/rendering/RenderObject.h

Index: sky/engine/core/rendering/RenderObject.h
diff --git a/sky/engine/core/rendering/RenderObject.h b/sky/engine/core/rendering/RenderObject.h
index 4a3b3bd7cd1a5ccd6c242d59b4dde9e302ae132f..b07c15c6be81a7ae24cf6077223b8791e695be78 100644
--- a/sky/engine/core/rendering/RenderObject.h
+++ b/sky/engine/core/rendering/RenderObject.h
@@ -338,7 +338,6 @@ public:
 
     bool hasTransform() const { return m_bitfields.hasTransform(); }
     bool hasClipPath() const { return style() && style()->clipPath(); }
-    bool hasHiddenBackface() const { return style() && style()->backfaceVisibility() == BackfaceVisibilityHidden; }
 
     inline bool preservesNewline() const;
 
@@ -361,9 +360,6 @@ public:
     // is true if the renderer returned is an ancestor of paintInvalidationContainer.
     RenderObject* container(const RenderBox* paintInvalidationContainer = 0, bool* paintInvalidationContainerSkipped = 0) const;
 
-    // TODO(esprehn): Remove this.
-    RenderObject* hoverAncestor() const { return parent(); }
-
     Element* offsetParent() const;
 
     void markContainingBlocksForLayout(bool scheduleRelayout = true, RenderObject* newRoot = 0, SubtreeLayoutScope* = 0);
@@ -501,6 +497,7 @@ public:
     const RenderView* containerForPaintInvalidation() const;
     const RenderBox* adjustCompositedContainerForSpecialAncestors(const RenderBox* paintInvalidationContainer) const;
 
+    // Overriden by RenderText for character length, used in line layout code.
     virtual unsigned length() const { return 1; }
 
     // FIXME(sky): Remove
@@ -592,8 +589,6 @@ public:
 
     RespectImageOrientationEnum shouldRespectImageOrientation() const;
 
-    bool isRelayoutBoundaryForInspector() const;
-
     bool onlyNeededPositionedMovementLayout() const { return m_bitfields.onlyNeededPositionedMovementLayout(); }
     void setOnlyNeededPositionedMovementLayout(bool b) { m_bitfields.setOnlyNeededPositionedMovementLayout(b); }