More master side changes for convergence with XFA.

fpdfsdk/include/fsdk_mgr.h

Index: fpdfsdk/include/fsdk_mgr.h
diff --git a/fpdfsdk/include/fsdk_mgr.h b/fpdfsdk/include/fsdk_mgr.h
index 5ddc8e6c57c3268ee8f6e8b852b84669d97c77e3..068731ee8fe0a13ae3e96be0418a2a3a9ae198f2 100644
--- a/fpdfsdk/include/fsdk_mgr.h
+++ b/fpdfsdk/include/fsdk_mgr.h
@@ -229,7 +229,14 @@ class CPDFSDK_Document {
   ~CPDFSDK_Document();
 
   CPDFSDK_InterForm* GetInterForm();
-  CPDF_Document* GetDocument() { return m_pDoc; }
+
+  // Gets the document object for the next layer down; for master this is
+  // a CPDF_Document, but for XFA it is a CPDFXFA_Document.
+  CPDF_Document* GetDocument() const { return m_pDoc; }
+
+  // Gets the CPDF_Document, either directly in master, or from the
+  // CPDFXFA_Document for XFA.
+  CPDF_Document* GetPDFDocument() const { return m_pDoc; }
 
   CPDFSDK_PageView* GetPageView(CPDF_Page* pPDFPage, FX_BOOL ReNew = TRUE);
   CPDFSDK_PageView* GetPageView(int nIndex);