Use process/control messages (instead of RVH messages) for layout tests.

content/shell/common/shell_messages.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.
 
 // Multiply-included file, no traditional include guard.
 #include <string>
 #include <vector>
 
 #include "base/values.h"
 #include "content/public/common/common_param_traits.h"
@@ skipping 85 matching lines @@
 IPC_MESSAGE_ROUTED1(ShellViewHostMsg_AudioDump,
                     std::vector<unsigned char> /* audio data */)
 
 IPC_MESSAGE_ROUTED0(ShellViewHostMsg_TestFinished)
 
 IPC_MESSAGE_ROUTED0(ShellViewHostMsg_ResetDone)
 
 // WebTestDelegate related.
 IPC_MESSAGE_ROUTED1(ShellViewHostMsg_OverridePreferences,
                     content::WebPreferences /* preferences */)
-IPC_MESSAGE_ROUTED1(ShellViewHostMsg_PrintMessage,
-                    std::string /* message */)
 IPC_MESSAGE_ROUTED0(ShellViewHostMsg_ClearDevToolsLocalStorage)
 IPC_MESSAGE_ROUTED2(ShellViewHostMsg_ShowDevTools,
                     std::string /* settings */,
                     std::string /* frontend_url */)
 IPC_MESSAGE_ROUTED2(ShellViewHostMsg_EvaluateInDevTools,
                     int /* call_id */,
                     std::string /* script */)
 IPC_MESSAGE_ROUTED0(ShellViewHostMsg_CloseDevTools)
 IPC_MESSAGE_ROUTED1(ShellViewHostMsg_GoToOffset,
                     int /* offset */)
@@ skipping 13 matching lines @@
                     content::LeakDetectionResult /* result */)
 
 IPC_MESSAGE_ROUTED1(ShellViewHostMsg_SetBluetoothManualChooser,
                     bool /* enable */)
 IPC_MESSAGE_ROUTED0(ShellViewHostMsg_GetBluetoothManualChooserEvents)
 IPC_MESSAGE_ROUTED1(ShellViewMsg_ReplyBluetoothManualChooserEvents,
                     std::vector<std::string> /* events */)
 IPC_MESSAGE_ROUTED2(ShellViewHostMsg_SendBluetoothManualChooserEvent,
                     std::string /* event */,
                     std::string /* argument */)