Add Print Selection support to Chrome. This change is fairly involved since ...

chrome/common/render_messages_internal.h

 // Copyright (c) 2009 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.
 
 // This header is meant to be included in multiple passes, hence no traditional
 // header guard.
 // See ipc_message_macros.h for explanation of the macros and passes.
 
 #include <string>
 #include <vector>
@@ skipping 82 matching lines @@
   IPC_MESSAGE_ROUTED0(ViewMsg_CaptureThumbnail)
 
   // Tells the render view that a ViewHostMsg_PaintRect message was processed.
   // This signals the render view that it can send another PaintRect message.
   IPC_MESSAGE_ROUTED0(ViewMsg_PaintRect_ACK)
 
   // Tells the render view to switch the CSS to print media type, renders every
   // requested pages and switch back the CSS to display media type.
   IPC_MESSAGE_ROUTED0(ViewMsg_PrintPages)
 
+  // Tells the render view that printing is done so it can clean up.
+  IPC_MESSAGE_ROUTED2(ViewMsg_PrintingDone,
+                      int /* document_cookie */,
+                      bool /* success */)
+
   // Tells the render view that a ViewHostMsg_ScrollRect message was processed.
   // This signals the render view that it can send another ScrollRect message.
   IPC_MESSAGE_ROUTED0(ViewMsg_ScrollRect_ACK)
 
   // Message payload is a blob that should be cast to WebInputEvent
   IPC_MESSAGE_ROUTED0(ViewMsg_HandleInputEvent)
 
   IPC_MESSAGE_ROUTED0(ViewMsg_MouseCaptureLost)
 
   // TODO(darin): figure out how this meshes with RestoreFocus
@@ skipping 1336 matching lines @@
   IPC_MESSAGE_CONTROL1(UtilityHostMsg_UnpackWebResource_Succeeded,
                        ListValue /* json data */)
 
   // Reply when the utility process has failed while unpacking and parsing a
   // web resource.  |error_message| is a user-readable explanation of what
   // went wrong.
   IPC_MESSAGE_CONTROL1(UtilityHostMsg_UnpackWebResource_Failed,
                        std::string /* error_message, if any */)
 
 IPC_END_MESSAGES(ViewHost)