Cast: Deduplicate event types in cast library.

media/cast/rtcp/rtcp_defines.h

Index: media/cast/rtcp/rtcp_defines.h
diff --git a/media/cast/rtcp/rtcp_defines.h b/media/cast/rtcp/rtcp_defines.h
index 5cc4a59a07a62cd6967599bcdea926ac5a1e85e0..f121742cae57e771a92ef244427f4b9d33770755 100644
--- a/media/cast/rtcp/rtcp_defines.h
+++ b/media/cast/rtcp/rtcp_defines.h
@@ -111,7 +111,7 @@ inline bool operator==(RtcpReceiverReferenceTimeReport lhs,
 
 // Struct used by raw event subscribers as an intermediate format before
 // sending off to the other side via RTCP.
-// (i.e., WindowedRtcpEventRtp{Sender,Receiver}Subscriber)
+// (i.e., {Sender,Receiver}RtcpEventSubscriber)
 struct RtcpEvent {
   RtcpEvent();
   ~RtcpEvent();
@@ -121,11 +121,10 @@ struct RtcpEvent {
   // Time of event logged.
   base::TimeTicks timestamp;
 
-  // Render/playout delay. Only set for kAudioPlayoutDelay and
-  // kVideoRenderDelay events.
+  // Render/playout delay. Only set for FRAME_PLAYOUT events.
   base::TimeDelta delay_delta;
 
-  // Only set for packet events. (kAudioPacketReceived, kVideoPacketReceived)
+  // Only set for packet events.
   uint16 packet_id;
 };