[Cast] Fix RtcpParser to parse negative playout delay deltas in receiver reports.

media/cast/net/rtcp/rtcp_utility.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/cast/net/rtcp/rtcp_utility.h"
 
 #include "base/logging.h"
 #include "media/cast/net/cast_transport_defines.h"
 
 namespace media {
@@ skipping 197 matching lines @@
       event_log.type = TranslateToLogEventFromWireFormat(
           static_cast<uint8>(event_type_and_timestamp_delta >> 12));
       event_log.event_timestamp =
           event_timestamp_base +
           base::TimeDelta::FromMilliseconds(
               event_type_and_timestamp_delta & 0xfff);
       if (event_log.type == PACKET_RECEIVED) {
         event_log.packet_id = delay_delta_or_packet_id;
       } else {
         event_log.delay_delta = base::TimeDelta::FromMilliseconds(
-            delay_delta_or_packet_id);
+            static_cast<int16>(delay_delta_or_packet_id));
       }
       frame_log.event_log_messages_.push_back(event_log);
     }
 
     receiver_log_.push_back(frame_log);
   }
 
   return true;
 }
 
@@ skipping 147 matching lines @@
     default:
       // If the sender adds new log messages we will end up here until we add
       // the new messages in the receiver.
       VLOG(1) << "Unexpected log message received: " << static_cast<int>(event);
       return UNKNOWN;
   }
 }
 
 }  // namespace cast
 }  // namespace media