Eliminate SwapOut message parameters, keeping state in RVHM instead.

content/common/view_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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "base/strings/string16.h"
@@ skipping 701 matching lines @@
   // equivalent (swapped out) frame in the destination process.
   IPC_STRUCT_MEMBER(int, source_routing_id)
 
   // The origin of the source frame.
   IPC_STRUCT_MEMBER(string16, source_origin)
 
   // The origin for the message's target.
   IPC_STRUCT_MEMBER(string16, target_origin)
 IPC_STRUCT_END()
 
-IPC_STRUCT_BEGIN(ViewMsg_SwapOut_Params)
-  // The identifier of the RenderProcessHost for the currently closing view.
-  //
-  // These first two parameters are technically redundant since they are
-  // needed only when processing the ACK message, and the processor
-  // theoretically knows both the process and route ID. However, this is
-  // difficult to figure out with our current implementation, so this
-  // information is duplicated here.
-  IPC_STRUCT_MEMBER(int, closing_process_id)
-
-  // The route identifier for the currently closing RenderView.
-  IPC_STRUCT_MEMBER(int, closing_route_id)
-
-  // The identifier of the RenderProcessHost for the new view attempting to
-  // replace the closing one above.
-  IPC_STRUCT_MEMBER(int, new_render_process_host_id)
-
-  // The identifier of the *request* the new view made that is causing the
-  // cross-site transition. This is *not* a route_id, but the request that we
-  // will resume once the ACK from the closing view has been received.
-  IPC_STRUCT_MEMBER(int, new_request_id)
-IPC_STRUCT_END()
-
 // Messages sent from the browser to the renderer.
 
 // Tells the renderer to cancel an opened date/time dialog.
 IPC_MESSAGE_ROUTED0(ViewMsg_CancelDateTimeDialog)
 
 // Get all savable resource links from current webpage, include main
 // frame and sub-frame.
 IPC_MESSAGE_ROUTED1(ViewMsg_GetAllSavableResourceLinksForCurrentPage,
                     GURL /* url of page which is needed to save */)
 
@@ skipping 363 matching lines @@
 // the browser has the option of sending a ViewMsg_CantFocus back to
 // the renderer.
 IPC_MESSAGE_ROUTED0(ViewMsg_CantFocus)
 
 // Instructs the renderer to invoke the frame's shouldClose method, which
 // runs the onbeforeunload event handler.  Expects the result to be returned
 // via ViewHostMsg_ShouldClose.
 IPC_MESSAGE_ROUTED0(ViewMsg_ShouldClose)
 
 // Instructs the renderer to swap out for a cross-site transition, including
-// running the unload event handler. See the struct above for more details.
-//
-// Expects a SwapOut_ACK message when finished, where the parameters are
-// echoed back.
-IPC_MESSAGE_ROUTED1(ViewMsg_SwapOut,
-                    ViewMsg_SwapOut_Params)
+// running the unload event handler. Expects a SwapOut_ACK message when
+// finished.
+IPC_MESSAGE_ROUTED0(ViewMsg_SwapOut)
 
 // Instructs the renderer to close the current page, including running the
 // onunload event handler.
 //
 // Expects a ClosePage_ACK message when finished.
 IPC_MESSAGE_ROUTED0(ViewMsg_ClosePage)
 
 // Notifies the renderer about ui theme changes
 IPC_MESSAGE_ROUTED0(ViewMsg_ThemeChanged)
 
@@ skipping 344 matching lines @@
 // Provides the result from running OnMsgShouldClose.  |proceed| matches the
 // return value of the the frame's shouldClose method (which includes the
 // onbeforeunload handler): true if the user decided to proceed with leaving
 // the page.
 IPC_MESSAGE_ROUTED3(ViewHostMsg_ShouldClose_ACK,
                     bool /* proceed */,
                     base::TimeTicks /* before_unload_start_time */,
                     base::TimeTicks /* before_unload_end_time */)
 
 // Indicates that the current renderer has swapped out, after a SwapOut
-// message. The parameters are just echoed from the SwapOut request.
-IPC_MESSAGE_ROUTED1(ViewHostMsg_SwapOut_ACK,
-                    ViewMsg_SwapOut_Params)
+// message.
+IPC_MESSAGE_ROUTED0(ViewHostMsg_SwapOut_ACK)
 
 // Indicates that the current page has been closed, after a ClosePage
 // message.
 IPC_MESSAGE_ROUTED0(ViewHostMsg_ClosePage_ACK)
 
 // Notifies the browser that media has started/stopped playing.
 IPC_MESSAGE_ROUTED4(ViewHostMsg_MediaNotification,
                     int64 /* player_cookie, distinguishes instances */,
                     bool /* has_video */,
                     bool /* has_audio */,
@@ skipping 826 matching lines @@
 // Since the browser keeps handles to the allocated transport DIBs, this
 // message is sent to tell the browser that it may release them when the
 // renderer is finished with them.
 IPC_MESSAGE_CONTROL1(ViewHostMsg_FreeTransportDIB,
                      TransportDIB::Id /* DIB id */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent ViewMsg, then ifdefs for platform specific ViewMsg, then platform
 // independent ViewHostMsg, then ifdefs for platform specific ViewHostMsg.