Rename sky/engine/bindings2 to sky/engine/bindings

sky/engine/bindings2/dart_callback.h

-// Copyright 2015 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_BINDINGS2_DART_CALLBACK_H_
-#define SKY_ENGINE_BINDINGS2_DART_CALLBACK_H_
-
-#include "dart/runtime/include/dart_api.h"
-#include "sky/engine/tonic/dart_persistent_value.h"
-
-namespace blink {
-
-class DartCallback {
- public:
-  DartCallback(DartState* dart_state,
-               Dart_Handle callback,
-               Dart_Handle& exception);
-  ~DartCallback();
-
-  bool handleEvent(int argc, Dart_Handle* argv);
-
-  bool IsIsolateAlive() const;
-  Dart_Isolate GetIsolate() const;
-
- private:
-  DartPersistentValue callback_;
-};
-}
-
-#endif  // SKY_ENGINE_BINDINGS2_DART_CALLBACK_H_