Cast: Increase max outstanding frames to 120

media/cast/cast_defines.h

Index: media/cast/cast_defines.h
diff --git a/media/cast/cast_defines.h b/media/cast/cast_defines.h
index c02fa2bfa72cfa07ee0f93d4b375f9a668ec9308..faafddb8850e309b403b25530a58fa44164da2ba 100644
--- a/media/cast/cast_defines.h
+++ b/media/cast/cast_defines.h
@@ -27,7 +27,10 @@ const uint32 kStartFrameId = UINT32_C(0xffffffff);
 // This is an important system-wide constant.  This limits how much history the
 // implementation must retain in order to process the acknowledgements of past
 // frames.
-const int kMaxUnackedFrames = 60;
+// This value is carefully choosen such that it fits in the 8-bits range for
+// frame IDs. It is also less than half of the full 8-bits range such that we
+// can handle wrap around and compare two frame IDs.
+const int kMaxUnackedFrames = 120;
 
 const int kStartRttMs = 20;
 const int64 kCastMessageUpdateIntervalMs = 33;