Add Observatory to sky dart_controller

sky/engine/bindings/builtin_natives.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SKY_ENGINE_BINDINGS_BUILTIN_NATIVES_H_
 #define SKY_ENGINE_BINDINGS_BUILTIN_NATIVES_H_
 
 #include "base/macros.h"
 #include "dart/runtime/include/dart_api.h"
 
 namespace blink {
 
 class BuiltinNatives {
  public:
+  enum IsolateType {
+    MainIsolate,
+    DartIOIsolate,
+  };
+
   static Dart_NativeFunction NativeLookup(Dart_Handle name,
                                           int argument_count,
                                           bool* auto_setup_scope);
   static const uint8_t* NativeSymbol(Dart_NativeFunction native_function);
 
-  static void Init();
+  static void Init(IsolateType isolate_type);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(BuiltinNatives);
 };
 
 }  // namespace blink
 
 #endif  // SKY_ENGINE_BINDINGS_BUILTIN_NATIVES_H_