Add dump() to SkClipStack to help with debugging.

include/core/SkRegion.h

Index: include/core/SkRegion.h
diff --git a/include/core/SkRegion.h b/include/core/SkRegion.h
index c9aa8daf880be37b4b5f3196d54f7ade25fdb2dc..20366bc63822441af294015df930c3eb34818770 100644
--- a/include/core/SkRegion.h
+++ b/include/core/SkRegion.h
@@ -244,9 +244,13 @@ public:
         kXOR_Op,        //!< exclusive-or the two regions
         /** subtract the first region from the op region */
         kReverseDifference_Op,
-        kReplace_Op     //!< replace the dst region with the op region
+        kReplace_Op,    //!< replace the dst region with the op region
+
+        kLastOp = kReplace_Op
     };
 
+    static const int kOpCnt = kLastOp + 1;
+
     /**
      *  Set this region to the result of applying the Op to this region and the
      *  specified rectangle: this = (this op rect).