Fix |Array| and iterator_util.h's Iterator operator->() behavior

mojo/public/cpp/bindings/lib/iterator_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 MOJO_PUBLIC_CPP_BINDINGS_LIB_ITERATOR_UTIL_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_ITERATOR_UTIL_H_
 
 #include <algorithm>
 
 #include "mojo/public/cpp/bindings/array.h"
@@ skipping 45 matching lines @@
       return *this;
     }
     Iterator operator--(int) {
       Iterator original = *this;
       --it_;
       return original;
     }
     bool operator==(const Iterator& o) const { return o.it_ == it_; }
     bool operator!=(const Iterator& o) const { return o.it_ != it_; }
     typename Map<K, V>::KeyConstRefType operator*() { return it_.GetKey(); }
-    typename Map<K, V>::KeyConstRefType operator->() { return operator*(); }
+    const K* operator->() { return &it_.GetKey(); }
 
    private:
     typename Map<K, V>::MapIterator it_;
   };
 
   explicit MapKeyIterator(Map<K, V>* map) : map_(map) { MOJO_DCHECK(map); }
 
   size_t size() const { return map_->size(); }
   Iterator begin() const { return Iterator{map_->begin()}; }
   Iterator end() const { return Iterator{map_->end()}; }
@@ skipping 24 matching lines @@
       return *this;
     }
     Iterator operator--(int) {
       Iterator original = *this;
       --it_;
       return original;
     }
     bool operator==(const Iterator& o) const { return o.it_ == it_; }
     bool operator!=(const Iterator& o) const { return o.it_ != it_; }
     typename Map<K, V>::ValueRefType operator*() { return it_.GetValue(); }
-    typename Map<K, V>::ValueRefType operator->() { return operator*(); }
+    V* operator->() { return &it_.GetValue(); }
 
    private:
     typename Map<K, V>::MapIterator it_;
   };
 
   explicit MapValueIterator(Map<K, V>* map) : map_(map) { MOJO_DCHECK(map); }
   size_t size() const { return map_->size(); }
   Iterator begin() const { return Iterator{map_->begin()}; }
   Iterator end() const { return Iterator{map_->end()}; }
 
  private:
   Map<K, V>* const map_;
 };
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_ITERATOR_UTIL_H_