Merge to XFA: Remove CFX_SegmentedArray use from master.

third_party/base/stl_util.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_
 #define PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_
 
+#include "third_party/base/numerics/safe_conversions.h"
+
 namespace pdfium {
 
 // Test to see if a set, map, hash_set or hash_map contains a particular key.
 // Returns true if the key is in the collection.
 template <typename Collection, typename Key>
 bool ContainsKey(const Collection& collection, const Key& key) {
   return collection.find(key) != collection.end();
 }
 
 // Test to see if a collection like a vector contains a particular value.
 // Returns true if the value is in the collection.
 template <typename Collection, typename Value>
 bool ContainsValue(const Collection& collection, const Value& value) {
   return std::find(collection.begin(), collection.end(), value) !=
          collection.end();
 }
 
+// Convenience routine for "int-fected" code, so that the stl collection
+// size_t size() method return values will be checked.
+template <typename ResultType, typename Collection>
+ResultType CollectionSize(const Collection& collection) {
+  return pdfium::base::checked_cast<ResultType, size_t>(collection.size());
+}
+
 }  // namespace pdfium
 
 #endif  // PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_