Implement FPDF_VIEWERREF_GetName() API.

public/fpdfview.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 // NOTE: External docs refer to this file as "fpdfview.h", so do not rename
 // despite lack of consistency with other public files.
 
 #ifndef PUBLIC_FPDFVIEW_H_
@@ skipping 896 matching lines @@
 // Function: FPDF_VIEWERREF_GetDuplex
 //          Returns the paper handling option to be used when printing from
 //          the print dialog.
 // Parameters:
 //          document    -   Handle to the loaded document.
 // Return value:
 //          The paper handling option to be used when printing.
 DLLEXPORT FPDF_DUPLEXTYPE STDCALL
 FPDF_VIEWERREF_GetDuplex(FPDF_DOCUMENT document);
 
+// Function: FPDF_VIEWERREF_GetName
+//          Gets the contents for a viewer ref, with a given key. The value must
+//          be of type "name".
+// Parameters:
+//          document    -   Handle to the loaded document.
+//          key         -   Name of the key in the viewer pref dictionary.
+//          buffer      -   A string to write the contents of the key to.
+//          length      -   Length of the buffer.
+// Return value:
+//          The number of bytes in the contents, including the NULL terminator.
+//          Thus if the return value is 0, then that indicates an error, such
+//          as when |document| is invalid or |buffer| is NULL. If |length| is
+//          less than the returned length, or |buffer| is NULL, |buffer| will
+//          not be modified.
+DLLEXPORT unsigned long STDCALL FPDF_VIEWERREF_GetName(FPDF_DOCUMENT document,
+                                                       FPDF_BYTESTRING key,
+                                                       char* buffer,
+                                                       unsigned long length);
+
 // Function: FPDF_CountNamedDests
 //          Get the count of named destinations in the PDF document.
 // Parameters:
 //          document    -   Handle to a document
 // Return value:
 //          The count of named destinations.
 DLLEXPORT FPDF_DWORD STDCALL FPDF_CountNamedDests(FPDF_DOCUMENT document);
 
 // Function: FPDF_GetNamedDestByName
 //          Get a the destination handle for the given name.
@@ skipping 45 matching lines @@
 // Function: FPDF_BStr_Clear
 //          Helper function to clear a byte string.
 DLLEXPORT FPDF_RESULT STDCALL FPDF_BStr_Clear(FPDF_BSTR* str);
 #endif  // PDF_ENABLE_XFA
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // PUBLIC_FPDFVIEW_H_