Send PING to check the status of the SPDY connection.

net/http/http_network_transaction.cc

 // Copyright (c) 2011 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.
 
 #include "net/http/http_network_transaction.h"
 
 #include <set>
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 1184 matching lines @@
     // portion of our request) only to find a connection error when we try to
     // read from (or finish writing to) the socket.
     case ERR_CONNECTION_RESET:
     case ERR_CONNECTION_CLOSED:
     case ERR_CONNECTION_ABORTED:
       if (ShouldResendRequest(error)) {
         ResetConnectionAndRequestForResend();
         error = OK;
       }
       break;
+
+      // Add one more error case for spdy_session's ping message failing.
   }
   return error;
 }
 
 void HttpNetworkTransaction::ResetStateForRestart() {
   ResetStateForAuthRestart();
   stream_.reset();
 }
 
 void HttpNetworkTransaction::ResetStateForAuthRestart() {
@@ skipping 123 matching lines @@
       description = base::StringPrintf("Unknown state 0x%08X (%u)", state,
                                        state);
       break;
   }
   return description;
 }
 
 #undef STATE_CASE
 
 }  // namespace net