Run Dart closures invoked from JS in the correct Zone

Source/bindings/dart/DartJsInterop.cpp

Index: Source/bindings/dart/DartJsInterop.cpp
diff --git a/Source/bindings/dart/DartJsInterop.cpp b/Source/bindings/dart/DartJsInterop.cpp
index ba91725a100f51edf6d2faf6e136f438f1d9ab7d..063acfce671c07fbb4edc9686f7ab845f2c945bd 100644
--- a/Source/bindings/dart/DartJsInterop.cpp
+++ b/Source/bindings/dart/DartJsInterop.cpp
@@ -80,23 +80,27 @@ static void functionInvocationCallback(const v8::FunctionCallbackInfo<v8::Value>
     DartDOMData* domData = DartDOMData::current();
     ASSERT(domData);
     ASSERT(DartUtilities::isFunction(domData, handle));
-
-    Vector<Dart_Handle> dartFunctionArgs;
     ASSERT(args.Length() == 1 || args.Length() == 2);
+
+    v8::Local<v8::Array> argsList = args[args.Length()-1].As<v8::Array>();
+    uint32_t argsListLength = argsList->Length();
+    Dart_Handle dartFunctionArgs;
+    uint32_t offset = 0;
     // If there is 1 argument, we assume it is a v8:Array or arguments, if
     // there are 2 arguments, the first argument is "this" and the second
     // argument is an array of arguments.
-    if (args.Length() > 1) {
-        dartFunctionArgs.append(JsInterop::toDart(args[0]));
+    if (args.Length() == 1) {
+        dartFunctionArgs = Dart_NewList(argsListLength);
+    } else {
+        dartFunctionArgs = Dart_NewList(argsListLength + 1);
+        Dart_ListSetAt(dartFunctionArgs, offset++, JsInterop::toDart(args[0]));
     }
 
-    v8::Local<v8::Array> argsList = args[args.Length()-1].As<v8::Array>();
-    uint32_t argsListLength = argsList->Length();
     for (uint32_t i = 0; i < argsListLength; i++) {
-        dartFunctionArgs.append(JsInterop::toDart(argsList->Get(i)));
+        Dart_ListSetAt(dartFunctionArgs, i + offset, JsInterop::toDart(argsList->Get(i)));
     }
 
-    setJsReturnValue(domData, args, Dart_InvokeClosure(handle, dartFunctionArgs.size(), dartFunctionArgs.data()));
+    setJsReturnValue(domData, args, Dart_InvokeClosure(handle, 1, &dartFunctionArgs));
 }
 
 static v8::Local<v8::ObjectTemplate> setupInstanceTemplate(v8::Local<v8::FunctionTemplate> proxyTemplate)
@@ -216,12 +220,20 @@ v8::Local<v8::Value> JsInterop::fromDart(DartDOMData* domData, Dart_Handle handl
         return object->localV8Object();
     }
 
-    if (DartUtilities::isFunction(domData, handle)) {
+    // call _wrapToJs
+    Dart_Handle wrappedValue = Dart_Invoke(domData->jsLibrary(), Dart_NewStringFromCString("_wrapToJs"), 1, &handle);
+
+    if (DartUtilities::isFunction(domData, wrappedValue)) {
         v8::Local<v8::Object> functionProxy = dartFunctionTemplate()->InstanceTemplate()->NewInstance();
-        DartHandleProxy::writePointerToProxy(functionProxy, handle);
+        DartHandleProxy::writePointerToProxy(functionProxy, wrappedValue);
         // The raw functionProxy doesn't behave enough like a true JS function
         // so we wrap it in a true JS function.
-        return domData->jsInteropData()->wrapDartFunction()->Call(functionProxy, 0, 0);
+        v8::Local<v8::Function> jsFunction = v8::Local<v8::Function>::Cast(domData->jsInteropData()->wrapDartFunction()->Call(functionProxy, 0, 0));
+        v8::Isolate* v8Isolate = v8::Isolate::GetCurrent();
+        jsFunction->SetHiddenValue(v8::String::NewFromUtf8(v8Isolate, "dartProxy"), v8::Boolean::New(v8Isolate, true));
+        v8::Local<v8::External> external = v8::External::New(v8Isolate, wrappedValue);
+        jsFunction->SetHiddenValue(v8::String::NewFromUtf8(v8Isolate, "dartFunction"), external);
+        return jsFunction;
     }
 
     v8::Local<v8::Object> proxy;
@@ -260,17 +272,18 @@ Dart_Handle JsInterop::toDart(v8::Local<v8::Value> v8Handle)
     if (handle)
         return handle;
 
-    // Unwrap objects passed from Dart to JS that are being passed back to
-    // Dart. FIXME: we do not yet handle unwrapping JS functions passed
-    // from Dart to JS as we have to wrap them with true JS Function objects.
-    // If this use case is important we can support it at the cost of hanging
-    // an extra expando off the JS function wrapping the Dart function.
+    // Unwrap objects passed from Dart to JS that are being passed back to Dart.
     if (DartHandleProxy::isDartProxy(v8Handle)) {
+        v8::Isolate* v8Isolate = v8::Isolate::GetCurrent();
+        v8::Local<v8::Value> hiddenValue = v8Handle.As<v8::Object>()->GetHiddenValue(v8::String::NewFromUtf8(v8Isolate, "dartFunction"));
+        if (*hiddenValue && hiddenValue->IsExternal()) {
+            Dart_Handle dartHandle = static_cast<Dart_Handle>(v8::External::Cast(*hiddenValue)->Value());
+            return dartHandle;
+        }
         DartScriptValue* scriptValue = DartHandleProxy::readPointerFromProxy(v8Handle);
         ASSERT(scriptValue->isIsolateAlive());
         return scriptValue->value();
     }
-
     return JsObject::toDart(object);
 }