Add DISALLOW_COPY_AND_ASSIGN to subclasses of ValueObject and make ValueObject copyable.

runtime/vm/scavenger.cc

 // Copyright (c) 2011, 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.
 
 #include "vm/scavenger.h"
 
 #include <algorithm>
 #include <map>
 #include <utility>
 
@@ skipping 44 matching lines @@
   BoolScope(bool* addr, bool value) : _addr(addr), _value(*addr) {
     *_addr = value;
   }
   ~BoolScope() {
     *_addr = _value;
   }
 
  private:
   bool* _addr;
   bool _value;
+
+  DISALLOW_COPY_AND_ASSIGN(BoolScope);
 };
 
 
 class ScavengerVisitor : public ObjectPointerVisitor {
  public:
   explicit ScavengerVisitor(Isolate* isolate, Scavenger* scavenger)
       : ObjectPointerVisitor(isolate),
         scavenger_(scavenger),
         heap_(scavenger->heap_),
         vm_heap_(Dart::vm_isolate()->heap()),
@@ skipping 629 matching lines @@
   PeerTable::iterator it = peer_table_.find(raw_obj);
   return (it == peer_table_.end()) ? NULL : it->second;
 }
 
 
 int64_t Scavenger::PeerCount() const {
   return static_cast<int64_t>(peer_table_.size());
 }
 
 }  // namespace dart