Cast: Deduplicate event types in cast library.

media/cast/logging/receiver_time_offset_estimator_impl.h

Index: media/cast/logging/receiver_time_offset_estimator_impl.h
diff --git a/media/cast/logging/receiver_time_offset_estimator_impl.h b/media/cast/logging/receiver_time_offset_estimator_impl.h
index 0968bed2908d5bb47ea4cf3c14b789d3e9ad8f2a..1d0f6c8357f8c762f803e2f44d42c7d9d261c551 100644
--- a/media/cast/logging/receiver_time_offset_estimator_impl.h
+++ b/media/cast/logging/receiver_time_offset_estimator_impl.h
@@ -13,10 +13,10 @@
 namespace media {
 namespace cast {
 
-// This implementation listens to three types of events:
-// 1. kVideoFrameEncoded (sender side)
-// 2. kVideoAckSent (receiver side)
-// 3. kVideoAckReceived (sender side)
+// This implementation listens to three types of video events:
+// 1. FRAME_ENCODED (sender side)
+// 2. FRAME_ACK_SENT (receiver side)
+// 3. FRAME_ACK_RECEIVED (sender side)
 // There is a causal relationship between these events in that these events
 // must happen in order. This class obtains the lower and upper bounds for
 // the offset by taking the difference of timestamps (2) - (1) and (2) - (3),