Fix contants; RT-enable WebView pt2

 Bug: 15838537

 * Fix kSync_UIRedrawRequired constant value (woops)
 * Tell CanvasContext that WebView is now rt-safe

Change-Id: Idf15cf21115c2ca24b8ccd00025e8502864cd87c
diff --git a/libs/hwui/renderthread/DrawFrameTask.h b/libs/hwui/renderthread/DrawFrameTask.h
index 96f0add..243cc5d 100644
--- a/libs/hwui/renderthread/DrawFrameTask.h
+++ b/libs/hwui/renderthread/DrawFrameTask.h
@@ -41,7 +41,7 @@
 
 enum SyncResult {
     kSync_OK = 0,
-    kSync_UIRedrawRequired = 1 << 1,
+    kSync_UIRedrawRequired = 1 << 0,
 };
 
 /*