Cast: Fix rtcp event dedup logic in rtcp_receiver.

media/cast/rtcp/rtcp_utility.h

Index: media/cast/rtcp/rtcp_utility.h
diff --git a/media/cast/rtcp/rtcp_utility.h b/media/cast/rtcp/rtcp_utility.h
index 8d6d00ef82a614af9fe50ff4155d9a844380a789..fa8574406b5fe1cdf9e9bf0d5d5812e10a98c585 100644
--- a/media/cast/rtcp/rtcp_utility.h
+++ b/media/cast/rtcp/rtcp_utility.h
@@ -7,6 +7,7 @@
 
 #include "media/cast/cast_config.h"
 #include "media/cast/cast_defines.h"
+#include "media/cast/logging/logging_defines.h"
 #include "media/cast/rtcp/rtcp_defines.h"
 
 namespace media {
@@ -343,6 +344,14 @@ class RtcpParser {
   DISALLOW_COPY_AND_ASSIGN(RtcpParser);
 };
 
+// Converts a log event type to an integer value.
+// NOTE: We have only allocated 4 bits to represent the type of event over the
+// wire. Therefore, this function can only return values from 0 to 15.
+uint8 ConvertEventTypeToWireFormat(CastLoggingEvent event);
+
+// The inverse of |ConvertEventTypeToWireFormat()|.
+CastLoggingEvent TranslateToLogEventFromWireFormat(uint8 event);
+
 }  // namespace cast
 }  // namespace media