[content shell] change how the main render view is picked for layout tests

content/shell/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 "content/public/common/common_param_traits.h"
 #include "ipc/ipc_message_macros.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 #define IPC_MESSAGE_START ShellMsgStart
 
 // Sets the current working directory to use for layout tests.
 IPC_MESSAGE_ROUTED1(ShellViewMsg_SetCurrentWorkingDirectory,
                     FilePath /* current_working_directory */)
 
 // Tells the render view to capture a text dump of the page. The render view
 // responds with a ShellViewHostMsg_TextDump.
 IPC_MESSAGE_ROUTED3(ShellViewMsg_CaptureTextDump,
                     bool /* as_text */,
                     bool /* printing */,
                     bool /* recursive */)
 
 // Tells the render view to capture an image of the page. The render view
 // responds with a ShellViewHostMsg_ImageDump.
 IPC_MESSAGE_ROUTED1(ShellViewMsg_CaptureImageDump,
                     std::string /* expected pixel hash */)
 
-// Tells the render view that it should register itself as main window for the
-// layout test.
-IPC_MESSAGE_ROUTED0(ShellViewMsg_SetIsMainWindow)
-
 // Tells the renderer to reset all test runners.
 IPC_MESSAGE_CONTROL0(ShellViewMsg_ResetAll)
 
 // Send a text dump of the WebContents to the render host.
 IPC_MESSAGE_ROUTED1(ShellViewHostMsg_TextDump,
                     std::string /* dump */)
 
 // Send an image dump of the WebContents to the render host.
 IPC_MESSAGE_ROUTED2(ShellViewHostMsg_ImageDump,
                     std::string /* actual pixel hash */,
@@ skipping 12 matching lines @@
 IPC_MESSAGE_ROUTED0(ShellViewHostMsg_DumpChildFramesAsText)
 IPC_MESSAGE_ROUTED0(ShellViewHostMsg_SetPrinting)
 IPC_MESSAGE_ROUTED1(
     ShellViewHostMsg_SetShouldStayOnPageAfterHandlingBeforeUnload,
     bool /* should_stay_on_page */)
 IPC_MESSAGE_ROUTED0(ShellViewHostMsg_WaitUntilDone)
 
 IPC_MESSAGE_ROUTED2(ShellViewHostMsg_NotImplemented,
                     std::string /* object_name */,
                     std::string /* property_name */)