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

net/spdy/spdy_proxy_client_socket.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_SPDY_SPDY_PROXY_CLIENT_SOCKET_H_
 #define NET_SPDY_SPDY_PROXY_CLIENT_SOCKET_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 69 matching lines @@
 
   // Socket implementation.
   int Read(IOBuffer* buf,
            int buf_len,
            const CompletionCallback& callback) override;
   int Write(IOBuffer* buf,
             int buf_len,
             const CompletionCallback& callback) override;
   int SetReceiveBufferSize(int32_t size) override;
   int SetSendBufferSize(int32_t size) override;
+  int SetDoNotFragment(bool do_not_fragment) override;
   int GetPeerAddress(IPEndPoint* address) const override;
   int GetLocalAddress(IPEndPoint* address) const override;
 
   // SpdyStream::Delegate implementation.
   void OnRequestHeadersSent() override;
   SpdyResponseHeadersStatus OnResponseHeadersUpdated(
       const SpdyHeaderBlock& response_headers) override;
   void OnDataReceived(std::unique_ptr<SpdyBuffer> buffer) override;
   void OnDataSent() override;
   void OnTrailers(const SpdyHeaderBlock& trailers) override;
@@ skipping 77 matching lines @@
   // Only used for posting write callbacks. Weak pointers created by this
   // factory are invalidated in Disconnect().
   base::WeakPtrFactory<SpdyProxyClientSocket> write_callback_weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SpdyProxyClientSocket);
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_PROXY_CLIENT_SOCKET_H_