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

core/fpdfdoc/include/cpdf_bookmarktree.h

Index: core/fpdfdoc/include/cpdf_bookmarktree.h
diff --git a/core/fpdfdoc/include/cpdf_bookmarktree.h b/core/fpdfdoc/include/cpdf_bookmarktree.h
new file mode 100644
index 0000000000000000000000000000000000000000..f496053383b0eb1311935b7de84c58c9d8fb4445
--- /dev/null
+++ b/core/fpdfdoc/include/cpdf_bookmarktree.h
@@ -0,0 +1,26 @@
+// 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_INCLUDE_CPDF_BOOKMARKTREE_H_
+#define CORE_FPDFDOC_INCLUDE_CPDF_BOOKMARKTREE_H_
+
+#include "core/fpdfdoc/include/cpdf_bookmark.h"
+
+class CPDF_Document;
+
+class CPDF_BookmarkTree {
+ public:
+  explicit CPDF_BookmarkTree(CPDF_Document* pDoc) : m_pDocument(pDoc) {}
+
+  CPDF_Bookmark GetFirstChild(const CPDF_Bookmark& parent) const;
+  CPDF_Bookmark GetNextSibling(const CPDF_Bookmark& bookmark) const;
+  CPDF_Document* GetDocument() const { return m_pDocument; }
+
+ private:
+  CPDF_Document* const m_pDocument;
+};
+
+#endif  // CORE_FPDFDOC_INCLUDE_CPDF_BOOKMARKTREE_H_