Changes to pass the current isolate to all runtime and native calls.

runtime/vm/heap.h

 // 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.
 
 #ifndef VM_HEAP_H_
 #define VM_HEAP_H_
 
 #include "vm/allocation.h"
 #include "vm/flags.h"
 #include "vm/globals.h"
@@ skipping 70 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(Heap);
 };
 
 
 #if defined(DEBUG)
 class NoGCScope : public StackResource {
  public:
   NoGCScope();
   ~NoGCScope();
  private:
-  Isolate* isolate_;
-
   DISALLOW_COPY_AND_ASSIGN(NoGCScope);
 };
 #else  // defined(DEBUG)
 class NoGCScope : public ValueObject {
  public:
   NoGCScope() {}
  private:
   DISALLOW_COPY_AND_ASSIGN(NoGCScope);
 };
 #endif  // defined(DEBUG)
 
 }  // namespace dart
 
 #endif  // VM_HEAP_H_