Do more CBA_FontMap initialization in the ctor and header.

Change-Id: I705a49198a91b67aa403beea4446095a6a359259
Reviewed-on: https://pdfium-review.googlesource.com/39415
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/fpdfsdk/formfiller/cba_fontmap.cpp b/fpdfsdk/formfiller/cba_fontmap.cpp
index ae0cc80..98464cb 100644
--- a/fpdfsdk/formfiller/cba_fontmap.cpp
+++ b/fpdfsdk/formfiller/cba_fontmap.cpp
@@ -23,14 +23,8 @@
 CBA_FontMap::CBA_FontMap(CPDFSDK_Annot* pAnnot,
                          CFX_SystemHandler* pSystemHandler)
     : CPWL_FontMap(pSystemHandler),
-      m_pDocument(nullptr),
-      m_pAnnotDict(nullptr),
-      m_pDefaultFont(nullptr),
-      m_sAPType("N") {
-  CPDF_Page* pPage = pAnnot->GetPDFPage();
-
-  m_pDocument = pPage->GetDocument();
-  m_pAnnotDict = pAnnot->GetPDFAnnot()->GetAnnotDict();
+      m_pDocument(pAnnot->GetPDFPage()->GetDocument()),
+      m_pAnnotDict(pAnnot->GetPDFAnnot()->GetAnnotDict()) {
   Initialize();
 }
 
diff --git a/fpdfsdk/formfiller/cba_fontmap.h b/fpdfsdk/formfiller/cba_fontmap.h
index 9d9f2e0..0ca07eb 100644
--- a/fpdfsdk/formfiller/cba_fontmap.h
+++ b/fpdfsdk/formfiller/cba_fontmap.h
@@ -36,11 +36,11 @@
   CPDF_Font* GetAnnotDefaultFont(ByteString* csNameTag);
   void AddFontToAnnotDict(CPDF_Font* pFont, const ByteString& sAlias);
 
-  UnownedPtr<CPDF_Document> m_pDocument;
-  UnownedPtr<CPDF_Dictionary> m_pAnnotDict;
+  UnownedPtr<CPDF_Document> const m_pDocument;
+  UnownedPtr<CPDF_Dictionary> const m_pAnnotDict;
   UnownedPtr<CPDF_Font> m_pDefaultFont;
   ByteString m_sDefaultFontName;
-  ByteString m_sAPType;
+  ByteString m_sAPType = "N";
 };
 
 #endif  // FPDFSDK_FORMFILLER_CBA_FONTMAP_H_