Split fpdfsdk/fsdk_baseform.h into individual classes.

This CL moves classes in fsdk_baseform.h to their own files.
Classes include CPDFSDK_Widget, CBA_AnnotIterator, CPDFSDK_XFAWidget,
PDFSDK_FieldAction, and CPDFSDK_Interform.

Review-Url: https://codereview.chromium.org/2252723002
diff --git a/fpdfsdk/javascript/PublicMethods.cpp b/fpdfsdk/javascript/PublicMethods.cpp
index 01bcfac..1dfac93 100644
--- a/fpdfsdk/javascript/PublicMethods.cpp
+++ b/fpdfsdk/javascript/PublicMethods.cpp
@@ -11,6 +11,7 @@
 
 #include "core/fpdfdoc/include/cpdf_interform.h"
 #include "core/fxcrt/include/fx_ext.h"
+#include "fpdfsdk/include/cpdfsdk_interform.h"
 #include "fpdfsdk/include/fsdk_mgr.h"
 #include "fpdfsdk/javascript/Field.h"
 #include "fpdfsdk/javascript/JS_Define.h"