Add DISALLOW_COPY_AND_ASSIGN to subclasses of ValueObject and make ValueObject copyable.

runtime/vm/hash_map.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_HASH_MAP_H_
 #define VM_HASH_MAP_H_
 
 namespace dart {
 
 template <typename KeyValueTrait>
@@ skipping 32 matching lines @@
   void ResizeLists(intptr_t new_size);
   uword Bound(uword value) const { return value & (array_size_ - 1); }
 
   intptr_t array_size_;
   intptr_t lists_size_;
   intptr_t count_;  // The number of values stored in the HashMap.
   HashMapListElement* array_;  // Primary store - contains the first value
   // with a given hash.  Colliding elements are stored in linked lists.
   HashMapListElement* lists_;  // The linked lists containing hash collisions.
   intptr_t free_list_head_;  // Unused elements in lists_ are on the free list.
+
+  // Disallow operator=. Use public copy constructor to copy instead.
+  DirectChainedHashMap<KeyValueTrait>& operator=(
+      const DirectChainedHashMap& other);
 };
 
 
 template <typename KeyValueTrait>
 typename KeyValueTrait::Value
     DirectChainedHashMap<KeyValueTrait>::
         Lookup(typename KeyValueTrait::Key key) const {
   uword hash = static_cast<uword>(KeyValueTrait::Hashcode(key));
   uword pos = Bound(hash);
   if (KeyValueTrait::ValueOf(array_[pos].kv) != NULL) {
@@ skipping 149 matching lines @@
   }
 
   static inline bool IsKeyEqual(Pair kv, Key key) {
     return kv->Equals(key);
   }
 };
 
 }  // namespace dart
 
 #endif  // VM_HASH_MAP_H_