Split fpdfdoc/include/fpdf_doc.h into individual classes.

core/fpdfdoc/cpdf_pagelabel.h

+// Copyright 2016 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
+
+#ifndef CORE_FPDFDOC_CPDF_PAGELABEL_H_
+#define CORE_FPDFDOC_CPDF_PAGELABEL_H_
+
+#include "core/fxcrt/include/fx_string.h"
+
+class CPDF_Document;
+
+class CPDF_PageLabel {
+ public:
+  explicit CPDF_PageLabel(CPDF_Document* pDocument);
+
+  CFX_WideString GetLabel(int nPage) const;
+  int32_t GetPageByLabel(const CFX_ByteStringC& bsLabel) const;
+  int32_t GetPageByLabel(const CFX_WideStringC& wsLabel) const;
+
+ private:
+  CPDF_Document* const m_pDocument;
+};
+
+#endif  // CORE_FPDFDOC_CPDF_PAGELABEL_H_