Multiple sync channels if used in the same listener thread could result in ca...

ipc/ipc_sync_message_unittest.h

 // Copyright (c) 2006-2008 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 <string>
+
 #include "ipc/ipc_message_macros.h"
 
 IPC_BEGIN_MESSAGES(Test)
   IPC_SYNC_MESSAGE_CONTROL0_0(SyncChannelTestMsg_NoArgs)
 
   IPC_SYNC_MESSAGE_CONTROL0_1(SyncChannelTestMsg_AnswerToLife,
                               int /* answer */)
 
   IPC_SYNC_MESSAGE_CONTROL1_1(SyncChannelTestMsg_Double,
                               int /* in */,
                               int /* out */)
 
+  IPC_SYNC_MESSAGE_CONTROL0_1(SyncChannelNestedTestMsg_String,
+                              std::string)
+
   // out1 is false
   IPC_SYNC_MESSAGE_CONTROL0_1(Msg_C_0_1, bool)
 
   // out1 is true, out2 is 2
   IPC_SYNC_MESSAGE_CONTROL0_2(Msg_C_0_2, bool, int)
 
   // out1 is false, out2 is 3, out3 is "0_3"
   IPC_SYNC_MESSAGE_CONTROL0_3(Msg_C_0_3, bool, int, std::string)
 
   // in1 must be 1, out1 is true
@@ skipping 62 matching lines @@
   // in1 must be "3_3", in2 must be false, in3 must be 2, out1 is true, out2
   // is 32
   IPC_SYNC_MESSAGE_ROUTED3_2(Msg_R_3_2, std::string, bool, int, bool, int)
 
   // in1 must be 3, in2 must be "3_3", in3 must be true, out1 is "3_3", out2 is
   // 33, out3 is false
   IPC_SYNC_MESSAGE_ROUTED3_3(Msg_R_3_3, int, std::string, bool, std::string,
                              int, bool)
 
 IPC_END_MESSAGES(Test)