Changed StackZone and ApiZone to be containers for Zone.

runtime/vm/handles.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_HANDLES_H_
 #define VM_HANDLES_H_
 
 #include "vm/allocation.h"
 #include "vm/flags.h"
 
@@ skipping 158 matching lines @@
 
     // Accessors.
     intptr_t next_handle_slot() const { return next_handle_slot_; }
     void set_next_handle_slot(intptr_t next_handle_slot) {
       next_handle_slot_ = next_handle_slot;
     }
     HandlesBlock* next_block() const { return next_block_; }
     void set_next_block(HandlesBlock* next) { next_block_ = next; }
 
    private:
-    // Zap value used to indicate uninitialized handle area (debug purposes).
-    static const uword kZapUninitializedWord = 0xabababab;
-
     uword data_[kHandleSizeInWords * kHandlesPerChunk];  // Handles area.
     intptr_t next_handle_slot_;  // Next slot for allocation in current block.
     HandlesBlock* next_block_;  // Link to next block of handles.
 
     DISALLOW_COPY_AND_ASSIGN(HandlesBlock);
   };
 
   // Deletes all the allocated handle blocks.
   void DeleteAll();
   void DeleteHandleBlocks(HandlesBlock* blocks);
@@ skipping 127 matching lines @@
 };
 #endif  // defined(DEBUG)
 
 // Macro to start a no handles scope in the code.
 #define NOHANDLESCOPE(isolate)                                                \
     dart::NoHandleScope no_vm_internal_handles_scope_(isolate);
 
 }  // namespace dart
 
 #endif  // VM_HANDLES_H_