Moves the top_ and end_ words of the Scavenger into mutator thread.

runtime/vm/object_graph.cc

 // Copyright (c) 2014, 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/object_graph.h"
 
 #include "vm/dart.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 595 matching lines @@
 }
 
 
 intptr_t ObjectGraph::Serialize(WriteStream* stream,
                                 SnapshotRoots roots,
                                 bool collect_garbage) {
   if (collect_garbage) {
     isolate()->heap()->CollectAllGarbage();
   }
   // Current encoding assumes objects do not move, so promote everything to old.
-  isolate()->heap()->new_space()->Evacuate();
+  isolate()->heap()->new_space()->Evacuate(isolate()->mutator_thread());
   HeapIterationScope iteration_scope(true);
 
   RawObject* kRootAddress = reinterpret_cast<RawObject*>(kHeapObjectTag);
   const intptr_t kRootCid = kIllegalCid;
   RawObject* kStackAddress =
       reinterpret_cast<RawObject*>(kObjectAlignment + kHeapObjectTag);
 
   stream->WriteUnsigned(kObjectAlignment);
   stream->WriteUnsigned(kStackCid);
 
@@ skipping 28 matching lines @@
   intptr_t object_count = visitor.count();
   if (roots == kVM) {
     object_count += 1;  // root
   } else {
     object_count += 2;  // root and stack
   }
   return object_count;
 }
 
 }  // namespace dart