Merge the Sky Engine changes from the SkyDart branch

sky/engine/bindings2/dart_callback.cc

 // 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.
 
 #include "sky/engine/config.h"
 #include "sky/engine/bindings2/dart_callback.h"
 
+#include "sky/engine/tonic/dart_converter.h"
 #include "sky/engine/tonic/dart_error.h"
 #include "sky/engine/tonic/dart_state.h"
 
 namespace blink {
 
 DartCallback::DartCallback(DartState* dart_state,
                            Dart_Handle callback,
                            Dart_Handle& exception)
     : callback_(dart_state, callback) {
   if (!Dart_IsClosure(callback)) {
@@ skipping 12 matching lines @@
 Dart_Isolate DartCallback::GetIsolate() const {
   return callback_.dart_state()->isolate();
 }
 
 bool DartCallback::handleEvent(int argc, Dart_Handle* argv) {
   LogIfError(Dart_InvokeClosure(callback_.value(), argc, argv));
   return true;
 }
 
 }  // namespace blink