Remove some uses of STL map.

runtime/vm/zone.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_ZONE_H_
 #define VM_ZONE_H_
 
 #include "platform/utils.h"
 #include "vm/allocation.h"
 #include "vm/handles.h"
@@ skipping 158 matching lines @@
   // Structure for managing handles allocation.
   VMHandles handles_;
 
   // Used for chaining zones in order to allow unwinding of stacks.
   Zone* previous_;
 
   friend class StackZone;
   friend class ApiZone;
   template<typename T, typename B, typename Allocator>
   friend class BaseGrowableArray;
+  template<typename T, typename B, typename Allocator>
+  friend class BaseDirectChainedHashMap;
   DISALLOW_COPY_AND_ASSIGN(Zone);
 };
 
 
 class StackZone : public StackResource {
  public:
   // Create an empty zone and set is at the current zone for the Thread.
   explicit StackZone(Thread* thread) : StackResource(thread), zone_() {
     if (FLAG_trace_zones) {
       OS::PrintErr("*** Starting a new Stack zone 0x%" Px "(0x%" Px ")\n",
@@ skipping 96 matching lines @@
     memmove(reinterpret_cast<void*>(new_data),
             reinterpret_cast<void*>(old_data),
             old_len * kElementSize);
   }
   return new_data;
 }
 
 }  // namespace dart
 
 #endif  // VM_ZONE_H_