add new onClip* methods to SkCanvas

src/utils/SkCanvasStack.h

Index: src/utils/SkCanvasStack.h
===================================================================
--- src/utils/SkCanvasStack.h	(revision 13622)
+++ src/utils/SkCanvasStack.h	(working copy)
@@ -30,12 +30,13 @@
     virtual void removeCanvas(SkCanvas*) SK_OVERRIDE { SkDEBUGFAIL("Invalid Op"); }
 
     virtual void setMatrix(const SkMatrix& matrix) SK_OVERRIDE;
-    virtual bool clipRect(const SkRect&, SkRegion::Op, bool) SK_OVERRIDE;
-    virtual bool clipRRect(const SkRRect&, SkRegion::Op, bool) SK_OVERRIDE;
-    virtual bool clipPath(const SkPath&, SkRegion::Op, bool) SK_OVERRIDE;
-    virtual bool clipRegion(const SkRegion& deviceRgn,
-                            SkRegion::Op) SK_OVERRIDE;
 
+protected:
+    virtual void onClipRect(const SkRect&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE;
+    virtual void onClipRRect(const SkRRect&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE;
+    virtual void onClipPath(const SkPath&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE;
+    virtual void onClipRegion(const SkRegion&, SkRegion::Op) SK_OVERRIDE;
+
 private:
     void clipToZOrderedBounds();