Fix mac build

runtime/vm/os_macos.cc

 // 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.
 
 #include "vm/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "vm/os.h"
 
 #include <errno.h>  // NOLINT
 #include <limits.h>  // NOLINT
 #include <mach/mach.h>  // NOLINT
 #include <mach/clock.h>  // NOLINT
 #include <mach/mach_time.h>  // NOLINT
 #include <sys/time.h>  // NOLINT
 #include <sys/resource.h>  // NOLINT
 #include <unistd.h>  // NOLINT
 
 #include "platform/utils.h"
 #include "vm/isolate.h"
+#include "vm/zone.h"
 
 namespace dart {
 
 const char* OS::Name() {
   return "macos";
 }
 
 
 intptr_t OS::ProcessId() {
   return static_cast<intptr_t>(getpid());
@@ skipping 266 matching lines @@
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)