Bug 1524335: Make InOrderPacket take last_sequence_number by reference; r=dmajor

Differential Revision: https://phabricator.services.mozilla.com/D19694

--HG--
extra : rebase_source : ac4ef8f11e7b1b4975d1cd2e4c8985c6d040703d
extra : amend_source : 2440c041736e2408be3a7a670f2f69b1b6ab5215

media/webrtc/trunk/webrtc/modules/rtp_rtcp/source/rtp_receiver_impl.cc

@@ -29,7 +29,7 @@
 namespace webrtc {
 
 namespace {
-bool InOrderPacket(rtc::Optional<uint16_t> latest_sequence_number,
+bool InOrderPacket(const rtc::Optional<uint16_t>& latest_sequence_number,
                    uint16_t current_sequence_number) {
   if (!latest_sequence_number)
     return true;