Move the message definitions to their own files.

xfa/fwl/core/ifwl_form.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "xfa/fwl/core/ifwl_form.h"
 
 #include "third_party/base/ptr_util.h"
 #include "xfa/fde/tto/fde_textout.h"
-#include "xfa/fwl/core/cfwl_message.h"
+#include "xfa/fwl/core/cfwl_msgmouse.h"
 #include "xfa/fwl/core/cfwl_themebackground.h"
 #include "xfa/fwl/core/cfwl_themepart.h"
 #include "xfa/fwl/core/cfwl_themetext.h"
 #include "xfa/fwl/core/cfwl_widgetmgr.h"
 #include "xfa/fwl/core/fwl_noteimp.h"
 #include "xfa/fwl/core/ifwl_app.h"
 #include "xfa/fwl/core/ifwl_formproxy.h"
 #include "xfa/fwl/core/ifwl_themeprovider.h"
 #include "xfa/fwl/theme/cfwl_widgettp.h"
 
@@ skipping 861 matching lines @@
 
 uint32_t CFWL_SysBtn::GetPartState() const {
   if (IsDisabled())
     return CFWL_PartState_Disabled;
   if (m_dwState & FWL_SYSBUTTONSTATE_Pressed)
     return CFWL_PartState_Pressed;
   if (m_dwState & FWL_SYSBUTTONSTATE_Hover)
     return CFWL_PartState_Hovered;
   return CFWL_PartState_Normal;
 }