Fix a bug in passing the RTP header from P2PSocketHost to WebRtcLogggingHandlerHost.

chrome/browser/media/webrtc_rtp_dump_writer.cc

Index: chrome/browser/media/webrtc_rtp_dump_writer.cc
diff --git a/chrome/browser/media/webrtc_rtp_dump_writer.cc b/chrome/browser/media/webrtc_rtp_dump_writer.cc
index b982bfb1bf7f9b75d0e057cb0d4cc065116b27e2..aa9434e6280545cc494b8764e0922b622f4b172d 100644
--- a/chrome/browser/media/webrtc_rtp_dump_writer.cc
+++ b/chrome/browser/media/webrtc_rtp_dump_writer.cc
@@ -71,8 +71,9 @@ void WritePacketDumpHeaderBigEndian(const base::TimeTicks& start,
   base::WriteBigEndian(buffer, packet_length);
   buffer += sizeof(packet_length);
 
-  base::WriteBigEndian(buffer,
-                       (base::TimeTicks::Now() - start).InMilliseconds());
+  uint32 elapsed =
+      static_cast<uint32>((base::TimeTicks::Now() - start).InMilliseconds());
+  base::WriteBigEndian(buffer, elapsed);
 }
 
 // Append |src_len| bytes from |src| to |dest|.