Add RT-enabled reveal animator

 Bug: 16161431

 Also re-writes RevealAnimator to avoid using any listeners internally,
 removing the logic around shadowing the update listeners.

Change-Id: I6ed8126398eed971a87f20bccb7584c9acafbb6c
diff --git a/libs/hwui/RevealClip.h b/libs/hwui/RevealClip.h
index ece8498..07404cb 100644
--- a/libs/hwui/RevealClip.h
+++ b/libs/hwui/RevealClip.h
@@ -57,6 +57,10 @@
         return mShouldClip;
     }
 
+    float radius() const {
+        return mRadius;
+    }
+
     const SkPath* getPath() const {
         if (!mShouldClip) return NULL;