Remove include only fwl.h and IWYU.

xfa/include/fwl/core/fwl_widgetmgr.h

Index: xfa/include/fwl/core/fwl_widgetmgr.h
diff --git a/xfa/include/fwl/core/fwl_widgetmgr.h b/xfa/include/fwl/core/fwl_widgetmgr.h
index 2420f6927fecf65d565a179250aedbda405ee3f8..9486af5ef7069635ce372473aa41080f0bf6c8d1 100644
--- a/xfa/include/fwl/core/fwl_widgetmgr.h
+++ b/xfa/include/fwl/core/fwl_widgetmgr.h
@@ -7,9 +7,13 @@
 #ifndef XFA_INCLUDE_FWL_CORE_FWL_WIDGETMGR_H_
 #define XFA_INCLUDE_FWL_CORE_FWL_WIDGETMGR_H_
 
+#include "xfa/include/fwl/core/fwl_note.h"
+
 class IFWL_Widget;
-class IFWL_WidgetMgr;
-class IFWL_WidgetMgrDelegate;
+
+#define FWL_WGTMGR_DisableThread 0x00000001
+#define FWL_WGTMGR_DisableForm 0x00000002
+
 enum FWL_WGTRELATION {
   FWL_WGTRELATION_Parent = 0,
   FWL_WGTRELATION_Owner,
@@ -21,6 +25,7 @@ enum FWL_WGTRELATION {
   FWL_WGTRELATION_LastChild,
   FWL_WGTRELATION_SystemForm
 };
+
 class IFWL_WidgetMgr {
  public:
   virtual ~IFWL_WidgetMgr() {}
@@ -37,8 +42,7 @@ class IFWL_WidgetMgr {
 };
 IFWL_WidgetMgr* FWL_GetWidgetMgr();
 FX_BOOL FWL_WidgetIsChild(IFWL_Widget* parent, IFWL_Widget* find);
-#define FWL_WGTMGR_DisableThread 0x00000001
-#define FWL_WGTMGR_DisableForm 0x00000002
+
 class IFWL_WidgetMgrDelegate {
  public:
   virtual ~IFWL_WidgetMgrDelegate() {}