Add "reference" and "const_reference" typedefs to ScopedVector to enable it to support std::back_in…

base/memory/scoped_vector.h

 // Copyright (c) 2012 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 BASE_MEMORY_SCOPED_VECTOR_H_
 #define BASE_MEMORY_SCOPED_VECTOR_H_
 #pragma once
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/move.h"
 #include "base/stl_util.h"
 
 // ScopedVector wraps a vector deleting the elements from its
 // destructor.
 template <class T>
 class ScopedVector {
   MOVE_ONLY_TYPE_FOR_CPP_03(ScopedVector, RValue)
 
  public:
   typedef typename std::vector<T*>::iterator iterator;
   typedef typename std::vector<T*>::const_iterator const_iterator;
   typedef typename std::vector<T*>::reverse_iterator reverse_iterator;
   typedef typename std::vector<T*>::const_reverse_iterator
       const_reverse_iterator;
+  typedef typename std::vector<T*>::reference reference;
+  typedef typename std::vector<T*>::const_reference const_reference;
 
   ScopedVector() {}
   ~ScopedVector() { reset(); }
   ScopedVector(RValue& other) { swap(other); }
 
   ScopedVector& operator=(RValue& rhs) {
     swap(rhs);
     return *this;
   }
 
@@ skipping 57 matching lines @@
 
   // Like |erase()|, but doesn't delete the elements in [first, last).
   iterator weak_erase(iterator first, iterator last) {
     return v.erase(first, last);
   }
  private:
   std::vector<T*> v;
 };
 
 #endif  // BASE_MEMORY_SCOPED_VECTOR_H_