Remove include only fwl.h and IWYU.

xfa/src/fwl/src/theme/listboxtp.cpp

Index: xfa/src/fwl/src/theme/listboxtp.cpp
diff --git a/xfa/src/fwl/src/theme/listboxtp.cpp b/xfa/src/fwl/src/theme/listboxtp.cpp
index 4d440e4278b3874cc04149d90a114428242ab7be..7d7670036832fea13c5f7c24aada418bda4b20b5 100644
--- a/xfa/src/fwl/src/theme/listboxtp.cpp
+++ b/xfa/src/fwl/src/theme/listboxtp.cpp
@@ -4,9 +4,15 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
+#include "xfa/include/fwl/theme/listboxtp.h"
+
+#include "xfa/include/fwl/basewidget/fwl_listbox.h"
+#include "xfa/include/fwl/core/fwl_widget.h"
 #include "xfa/src/foxitlib.h"
+
 CFWL_ListBoxTP::CFWL_ListBoxTP() {}
 CFWL_ListBoxTP::~CFWL_ListBoxTP() {}
+
 FX_BOOL CFWL_ListBoxTP::IsValidWidget(IFWL_Widget* pWidget) {
   if (!pWidget)
     return FALSE;