Merge to XFA: Fix (nearly all) IWYU in fpdfskd/include/javascript/ headers.

Original Review URL: https://codereview.chromium.org/1060133002
TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1065103002
diff --git a/fpdfsdk/include/javascript/Field.h b/fpdfsdk/include/javascript/Field.h
index ba834b9..f9e5e49 100644
--- a/fpdfsdk/include/javascript/Field.h
+++ b/fpdfsdk/include/javascript/Field.h
@@ -7,6 +7,11 @@
 #ifndef _FIELD_H_
 #define _FIELD_H_
 
+#include <string>  // For std::wstring.
+
+// TODO(tsepez): include PWL_Wnd.h for PWL_Color after fixing its IWYU.
+#include "JS_Define.h"
+
 class Document;
 
 enum FIELD_PROP