Tidy PDF_ENABLE_XFA #ifdefs in fpdfsdk.

-- label matching #endifs
-- prefer #ifdef over #ifndef
-- consolidate some blocks.

R=ochang@chromium.org

Review URL: https://codereview.chromium.org/1484843002 .
diff --git a/fpdfsdk/src/fpdfeditpage.cpp b/fpdfsdk/src/fpdfeditpage.cpp
index 75ed27c..aff74d1 100644
--- a/fpdfsdk/src/fpdfeditpage.cpp
+++ b/fpdfsdk/src/fpdfeditpage.cpp
@@ -6,13 +6,14 @@
 
 #include "public/fpdf_edit.h"
 
+#include "fpdfsdk/include/fsdk_define.h"
+#include "public/fpdf_formfill.h"
+
 #ifdef PDF_ENABLE_XFA
 #include "../include/fpdfxfa/fpdfxfa_app.h"
 #include "../include/fpdfxfa/fpdfxfa_doc.h"
 #include "../include/fpdfxfa/fpdfxfa_page.h"
-#endif
-#include "fpdfsdk/include/fsdk_define.h"
-#include "public/fpdf_formfill.h"
+#endif  // PDF_ENABLE_XFA
 
 #if _FX_OS_ == _FX_ANDROID_
 #include "time.h"
@@ -83,15 +84,15 @@
   pPageDict->SetAt("Rotate", new CPDF_Number(0));
   pPageDict->SetAt("Resources", new CPDF_Dictionary);
 
-#ifndef PDF_ENABLE_XFA
-  CPDF_Page* pPage = new CPDF_Page;
-  pPage->Load(pDoc, pPageDict);
-  pPage->ParseContent();
-#else
+#ifdef PDF_ENABLE_XFA
   CPDFXFA_Page* pPage =
       new CPDFXFA_Page((CPDFXFA_Document*)document, page_index);
   pPage->LoadPDFPage(pPageDict);
-#endif
+#else   // PDF_ENABLE_XFA
+  CPDF_Page* pPage = new CPDF_Page;
+  pPage->Load(pDoc, pPageDict);
+  pPage->ParseContent();
+#endif  // PDF_ENABLE_XFA
 
   return pPage;
 }