Remove include only fwl.h and IWYU.

xfa/src/fwl/src/core/fwl_contentimp.cpp

Index: xfa/src/fwl/src/core/fwl_contentimp.cpp
diff --git a/xfa/src/fwl/src/core/fwl_contentimp.cpp b/xfa/src/fwl/src/core/fwl_contentimp.cpp
index 2d3eeed8c88001ce90952c977b83f051ab03b5e5..482cf12908f02fa0d8f93020f75fec985d71662e 100644
--- a/xfa/src/fwl/src/core/fwl_contentimp.cpp
+++ b/xfa/src/fwl/src/core/fwl_contentimp.cpp
@@ -4,13 +4,16 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#include "xfa/src/foxitlib.h"
 #include "xfa/src/fwl/src/core/include/fwl_contentimp.h"
+
+#include "xfa/include/fwl/core/fwl_content.h"
+#include "xfa/src/foxitlib.h"
 #include "xfa/src/fwl/src/core/include/fwl_noteimp.h"
 #include "xfa/src/fwl/src/core/include/fwl_targetimp.h"
 #include "xfa/src/fwl/src/core/include/fwl_threadimp.h"
 #include "xfa/src/fwl/src/core/include/fwl_widgetimp.h"
 #include "xfa/src/fwl/src/core/include/fwl_widgetmgrimp.h"
+
 FWL_ERR IFWL_Content::InsertWidget(IFWL_Widget* pChild, int32_t nIndex) {
   return static_cast<CFWL_ContentImp*>(GetImpl())->InsertWidget(pChild, nIndex);
 }