Fix layering violation in CPDF_Document::FromFPDFDocument().

core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp

Index: core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp
index b93cadd2666ee9240074ff6101360b5293e052b8..2dff76618750a4bf009c8fdd5158145b932c9ed0 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp
@@ -7,10 +7,6 @@
 #include "../../../include/fpdfapi/fpdf_parser.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 
-// static
-CPDF_Document* CPDF_Document::FromFPDFDocument(FPDF_DOCUMENT document) {
-  return static_cast<CPDF_Document*>(document);
-}
 
 CPDF_Document::CPDF_Document(CPDF_Parser* pParser)
     : CPDF_IndirectObjects(pParser) {