Update talk to 51664136.

R=mallinath@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2148004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4649 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/app/webrtc/mediaconstraintsinterface.h b/talk/app/webrtc/mediaconstraintsinterface.h
index a6b23c6..b14a0ec 100644
--- a/talk/app/webrtc/mediaconstraintsinterface.h
+++ b/talk/app/webrtc/mediaconstraintsinterface.h
@@ -86,6 +86,7 @@
   static const char kLeakyBucket[];  // googLeakyBucket
   // googTemporalLayeredScreencast
   static const char kTemporalLayeredScreencast[];
+  static const char kCpuOveruseDetection[];
 
   // Constraint keys for CreateOffer / CreateAnswer
   // Specified by the W3C PeerConnection spec