Start proxying CPDFSDK_Document methods through CPDFSDK_FormFillEnvironment

fpdfsdk/cpdfsdk_document.h

Index: fpdfsdk/cpdfsdk_document.h
diff --git a/fpdfsdk/cpdfsdk_document.h b/fpdfsdk/cpdfsdk_document.h
index 3da229cc674505f2c24b116f6208a80bd8538623..6cdc6f3adcdbb0c4b59a9649cc2afcc21bf7a774 100644
--- a/fpdfsdk/cpdfsdk_document.h
+++ b/fpdfsdk/cpdfsdk_document.h
@@ -29,8 +29,6 @@ class CPDFSDK_Document : public CFX_Observable<CPDFSDK_Document> {
                    CPDFSDK_FormFillEnvironment* pEnv);
   ~CPDFSDK_Document();
 
-  CPDFSDK_InterForm* GetInterForm();
-
   // Gets the document object for the next layer down; for master this is
   // a CPDF_Document, but for XFA it is a CPDFXFA_Document.
   UnderlyingDocumentType* GetUnderlyingDocument() const {
@@ -52,9 +50,6 @@ class CPDFSDK_Document : public CFX_Observable<CPDFSDK_Document> {
   }
 
 #ifdef PDF_ENABLE_XFA
-  // Gets the XFA document directly (XFA-only).
-  CPDFXFA_Document* GetXFADocument() const { return m_pDoc; }
-
   int GetPageViewCount() const { return m_pageMap.size(); }
 #endif  // PDF_ENABLE_XFA
 
@@ -94,6 +89,15 @@ class CPDFSDK_Document : public CFX_Observable<CPDFSDK_Document> {
   FX_BOOL ProcOpenAction();
 
  private:
+  friend class CPDFSDK_FormFillEnvironment;
+
+  CPDFSDK_InterForm* GetInterForm();
+
+#ifdef PDF_ENABLE_XFA
+  // Gets the XFA document directly (XFA-only).
+  CPDFXFA_Document* GetXFADocument() const { return m_pDoc; }
+#endif  // PDF_ENABLE_XFA
+
   std::map<UnderlyingPageType*, CPDFSDK_PageView*> m_pageMap;
   UnderlyingDocumentType* m_pDoc;
   std::unique_ptr<CPDFSDK_InterForm> m_pInterForm;