Use observed pointers in CPDFSDK_AnnotIterator.

fpdfsdk/cpdfsdk_annotiteration.h

Index: fpdfsdk/cpdfsdk_annotiteration.h
diff --git a/fpdfsdk/cpdfsdk_annotiteration.h b/fpdfsdk/cpdfsdk_annotiteration.h
new file mode 100644
index 0000000000000000000000000000000000000000..70edfd10aec4140d832872394ffedbf634b68a9d
--- /dev/null
+++ b/fpdfsdk/cpdfsdk_annotiteration.h
@@ -0,0 +1,31 @@
+// Copyright 2017 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 FPDFSDK_CPDFSDK_ANNOTITERATION_H_
+#define FPDFSDK_CPDFSDK_ANNOTITERATION_H_
+
+#include <vector>
+
+#include "fpdfsdk/cpdfsdk_annot.h"
+
+class CPDFSDK_PageView;
+
+class CPDFSDK_AnnotIteration {
+ public:
+  using const_iterator =
+      std::vector<CPDFSDK_Annot::ObservedPtr>::const_iterator;
+
+  CPDFSDK_AnnotIteration(CPDFSDK_PageView* pPageView, bool bReverse);
+  ~CPDFSDK_AnnotIteration();
+
+  const_iterator begin() const { return m_List.begin(); }
+  const_iterator end() const { return m_List.end(); }
+
+ private:
+  std::vector<CPDFSDK_Annot::ObservedPtr> m_List;
+};
+
+#endif  // FPDFSDK_CPDFSDK_ANNOTITERATION_H_