Add a SetDoNotFragment() method to DatagramSocket, and call this for

net/udp/udp_socket_unittest.cc

Index: net/udp/udp_socket_unittest.cc
diff --git a/net/udp/udp_socket_unittest.cc b/net/udp/udp_socket_unittest.cc
index 1f34ff6bba38663caa964b885d1e4ffbe55dfd91..6040d6c51e651c5cdabfc34bfebedffc24b1443c 100644
--- a/net/udp/udp_socket_unittest.cc
+++ b/net/udp/udp_socket_unittest.cc
@@ -581,6 +581,36 @@ TEST_F(UDPSocketTest, ServerGetPeerAddress) {
   EXPECT_EQ(rv, ERR_SOCKET_NOT_CONNECTED);
 }
 
+TEST_F(UDPSocketTest, ClientSetDoNotFragment) {
+  UDPClientSocket client(DatagramSocket::DEFAULT_BIND, RandIntCallback(), NULL,
+                         NetLog::Source());
+  IPAddress ip_address;
+  EXPECT_TRUE(ip_address.AssignFromIPLiteral("127.0.0.1"));

[mmenke, 2016/08/12 21:55:49]

Should we do it with IPv6, too?  The IPv6 path is more interesting.   Could just
use a loop, or duplicate the test.

[Ryan Hamilton, 2016/08/12 22:15:26]

Sure. Done.

+  IPEndPoint remote_address(ip_address, 80);
+  int rv = client.Connect(remote_address);
+  EXPECT_THAT(rv, IsOk());
+
+#if defined(OS_MACOSX)
+  EXPECT_EQ(ERR_NOT_IMPLEMENTED, client.SetDoNotFragment());
+#else
+  EXPECT_EQ(OK, client.SetDoNotFragment());
+#endif
+}
+
+TEST_F(UDPSocketTest, ServerSetDoNotFragment) {
+  IPEndPoint bind_address;
+  CreateUDPAddress("127.0.0.1", 0, &bind_address);
+  UDPServerSocket server(NULL, NetLog::Source());
+  int rv = server.Listen(bind_address);
+  EXPECT_THAT(rv, IsOk());
+
+#if defined(OS_MACOSX)
+  EXPECT_EQ(ERR_NOT_IMPLEMENTED, server.SetDoNotFragment());
+#else
+  EXPECT_EQ(OK, server.SetDoNotFragment());
+#endif
+}
+
 // Close the socket while read is pending.
 TEST_F(UDPSocketTest, CloseWithPendingRead) {
   IPEndPoint bind_address;