Add API function Dart_ZoneAllocate

runtime/vm/dart_api_impl.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 "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 2504 matching lines @@
     } else {
       *buffer = NULL;
     }
     delete debug_region;
   } else {
     *buffer = NULL;
     *buffer_size = 0;
   }
 }
 
+
+DART_EXPORT uint8_t* Dart_ZoneAllocate(intptr_t size) {
+  ApiZone* zone;
+  Isolate* isolate = Isolate::Current();
+  if (isolate != NULL) {
+    ApiState* state = isolate->api_state();
+    if (state == NULL) return NULL;
+    ApiLocalScope* scope = state->top_scope();
+    zone = &scope->zone();
+  } else {
+    ApiNativeScope* scope = ApiNativeScope::Current();
+    if (scope == NULL) return NULL;
+    zone = &scope->zone();
+  }
+  return reinterpret_cast<uint8_t*>(zone->Allocate(size));
+}
+
 }  // namespace dart