Change default timestamp to 64 bits in all webrtc directories.

webrtc/base/asynctcpsocket.cc

Index: webrtc/base/asynctcpsocket.cc
diff --git a/webrtc/base/asynctcpsocket.cc b/webrtc/base/asynctcpsocket.cc
index 120bcfbb64cddb7577d1200d6932b95ea7dbfba5..9ba46d7abc95882dad3de6b05599223f43891271 100644
--- a/webrtc/base/asynctcpsocket.cc
+++ b/webrtc/base/asynctcpsocket.cc
@@ -296,7 +296,7 @@ int AsyncTCPSocket::Send(const void *pv, size_t cb,
     return res;
   }
 
-  rtc::SentPacket sent_packet(options.packet_id, rtc::Time());
+  rtc::SentPacket sent_packet(options.packet_id, rtc::TimeMillis());
   SignalSentPacket(this, sent_packet);
 
   // We claim to have sent the whole thing, even if we only sent partial