Remove old session history logic.

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 640 matching lines @@
 
 // Indicates that the render view has been closed in respose to a
 // Close message.
 IPC_MESSAGE_CONTROL1(ViewHostMsg_Close_ACK,
                      int /* old_route_id */)
 
 // Indicates that the current page has been closed, after a ClosePage
 // message.
 IPC_MESSAGE_ROUTED0(ViewHostMsg_ClosePage_ACK)
 
-// Notifies the browser that we have session history information.
-IPC_MESSAGE_ROUTED1(ViewHostMsg_UpdateState,
-                    content::PageState /* state */)
-
 // Notifies the browser that we want to show a destination url for a potential
 // action (e.g. when the user is hovering over a link).
 IPC_MESSAGE_ROUTED1(ViewHostMsg_UpdateTargetURL,
                     GURL)
 
 // Sent when the document element is available for the top-level frame.  This
 // happens after the page starts loading, but before all resources are
 // finished.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_DocumentAvailableInMainFrame,
                     bool /* uses_temporary_zoom_level */)
@@ skipping 217 matching lines @@
                     int /* y */)
 
 #elif defined(OS_MACOSX)
 // Receives content of a web page as plain text.
 IPC_MESSAGE_ROUTED1(ViewMsg_GetRenderedTextCompleted, std::string)
 #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.