[merge m54] 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 a9f20f03cd996679200d127943de52e4ec3cd74c..2d7a714dcae2a26aaf364bb6bb10211637459570 100644
--- a/net/quic/chromium/quic_stream_factory.cc
+++ b/net/quic/chromium/quic_stream_factory.cc
@@ -67,7 +67,7 @@ enum CreateSessionFailure {
   CREATION_ERROR_CONNECTING_SOCKET,
   CREATION_ERROR_SETTING_RECEIVE_BUFFER,
   CREATION_ERROR_SETTING_SEND_BUFFER,
-  CREATION_ERROR_SETTING_NO_NOT_FRAGMENT,
+  CREATION_ERROR_SETTING_DO_NOT_FRAGMENT,
   CREATION_ERROR_MAX
 };
 
@@ -1704,8 +1704,9 @@ int QuicStreamFactory::ConfigureSocket(DatagramClientSocket* socket,
   }
 
   rv = socket->SetDoNotFragment();
-  if (rv != OK) {
-    HistogramCreateSessionFailure(CREATION_ERROR_SETTING_NO_NOT_FRAGMENT);
+  // SetDoNotFragment is not implemented on all platforms, so ignore errors.
+  if (rv != OK && rv != ERR_NOT_IMPLEMENTED) {
+    HistogramCreateSessionFailure(CREATION_ERROR_SETTING_DO_NOT_FRAGMENT);
     return rv;
   }