Ignore errors on SetDoNotFragment on platforms where it is not implemented.

net/quic/chromium/quic_stream_factory.cc

Index: net/quic/chromium/quic_stream_factory.cc
diff --git a/net/quic/chromium/quic_stream_factory.cc b/net/quic/chromium/quic_stream_factory.cc
index 2e7f2b67f77ed9bf075ae0616a1e758a26bcd95a..80e95cd19f3e94ce9efe7b257ba659abe4c50b04 100644
--- a/net/quic/chromium/quic_stream_factory.cc
+++ b/net/quic/chromium/quic_stream_factory.cc
@@ -1706,7 +1706,8 @@ int QuicStreamFactory::ConfigureSocket(DatagramClientSocket* socket,
   }
 
   rv = socket->SetDoNotFragment();
-  if (rv != OK) {
+  // SetDoNotFragment is not implemented on all platforms, so ignore errors.
+  if (rv != OK && rv != ERR_NOT_IMPLEMENTED) {

[Ryan Hamilton, 2016/08/27 21:55:56]

Alternatively, we could ignore ALL errors since it's not crucial if this does
not succeed. That being said, from UMA, it's only failing on OS X so this fix is
sufficient.

     HistogramCreateSessionFailure(CREATION_ERROR_SETTING_NO_NOT_FRAGMENT);

[mef, 2016/08/29 19:27:14]

nit: This should probably be CREATION_ERROR_SETTING_DO_NOT_FRAGMENT
(s/_NO_/_DO_/).

[Ryan Hamilton, 2016/08/29 19:42:48]

Good point. Will do so in a followup since this has been a bear to land)

[Ryan Hamilton, 2016/08/29 23:31:15]

Ok, I gave up on the CQ and landed this manually, so I fixed this. Done.

     return rv;
   }