Add dart_invoke to tonic for calls into App code.

sky/engine/core/dom/custom/custom_element.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/core/dom/custom/custom_element.h"
 
 #include "base/bind.h"
 #include "dart/runtime/include/dart_api.h"
 #include "sky/engine/core/dom/Document.h"
 #include "sky/engine/core/dom/Element.h"
 #include "sky/engine/core/dom/Microtask.h"
 #include "sky/engine/core/dom/custom/custom_element_callback_scope.h"
 #include "sky/engine/core/dom/custom/custom_element_registry.h"
 #include "sky/engine/tonic/dart_converter.h"
+#include "sky/engine/tonic/dart_invoke.h"
 #include "sky/engine/tonic/dart_state.h"
 #include "sky/engine/wtf/text/AtomicString.h"
 
 namespace blink {
 namespace {
 
 void ScheduleCallback(const base::Closure& callback) {
   if (auto* scope = CustomElementCallbackScope::Current()) {
     scope->Enqueue(callback);
   } else {
     Microtask::enqueueMicrotask(callback);
   }
 }
 
 void CallAttributeDidChangedCallback(RefPtr<Element> element,
                                      AtomicString name,
                                      AtomicString oldValue,
                                      AtomicString newValue) {
   auto* dart_state = element->document().elementRegistry().dart_state().get();
   if (!dart_state)
     return;
   DartState::Scope scope(dart_state);
   Dart_Handle wrapper = ToDart(element);
   Dart_Handle callback = Dart_NewStringFromCString("attributeChangedCallback");
   Dart_Handle args[] = {
     StringToDart(dart_state, name),
     StringToDart(dart_state, oldValue),
     StringToDart(dart_state, newValue),
   };
-  LogIfError(Dart_Invoke(wrapper, callback, arraysize(args), args));
+  DartInvokeAppField(wrapper, callback, arraysize(args), args);
 }
 
 void CallDidAttachedCallback(RefPtr<Element> element, RefPtr<Document> document) {
   auto* dart_state = document->elementRegistry().dart_state().get();
   if (!dart_state)
     return;
   DartState::Scope scope(dart_state);
   Dart_Handle wrapper = ToDart(element);
   Dart_Handle callback = Dart_NewStringFromCString("attachedCallback");
   LogIfError(Dart_Invoke(wrapper, callback, 0, nullptr));
@@ skipping 21 matching lines @@
 
 void CustomElement::DidAttach(Element* element, Document& document) {
   ScheduleCallback(base::Bind(CallDidAttachedCallback, element, &document));
 }
 
 void CustomElement::DidDetach(Element* element, Document& document) {
   ScheduleCallback(base::Bind(CallDidDetachedCallback, element, &document));
 }
 
 }  // namespace blink