fixes #43, remove => workaround

lib/runtime/dart/_isolate_helper.js

 var _isolate_helper = dart.defineLibrary(_isolate_helper, {});
 var core = dart.import(core);
 var _native_typed_data = dart.import(_native_typed_data);
 var _interceptors = dart.lazyImport(_interceptors);
 var _js_helper = dart.lazyImport(_js_helper);
 var isolate = dart.import(isolate);
 var _foreign_helper = dart.import(_foreign_helper);
 var _js_embedded_names = dart.import(_js_embedded_names);
 var collection = dart.import(collection);
 var async = dart.import(async);
@@ skipping 839 matching lines @@
       if (event == null) {
         this.checkOpenReceivePortsFromCommandLine();
         exports._globalState.maybeCloseWorker();
         return false;
       }
       event.process();
       return true;
     }
     [_runHelper]() {
       if (exports.globalWindow != null) {
-        let next = (() => {
+        let next = () => {
           if (!dart.notNull(this.runIteration()))
             return;
           async.Timer.run(next);
-        }).bind(this);
+        };
         dart.fn(next);
         next();
       } else {
         while (this.runIteration()) {
         }
       }
     }
     run() {
       if (!dart.notNull(exports._globalState.isWorker)) {
         this[_runHelper]();
@@ skipping 397 matching lines @@
       let isolate = exports._globalState.isolates.get(this[_isolateId]);
       if (isolate == null)
         return;
       if (this[_receivePort][_isClosed])
         return;
       let msg = _clone(message);
       if (dart.equals(isolate.controlPort, this[_receivePort])) {
         isolate.handleControlMessage(msg);
         return;
       }
-      exports._globalState.topEventLoop.enqueue(isolate, dart.fn((() => {
+      exports._globalState.topEventLoop.enqueue(isolate, dart.fn(() => {
         if (!dart.notNull(this[_receivePort][_isClosed])) {
           this[_receivePort][_add](msg);
         }
-      }).bind(this)), `receive ${message}`);
+      }), `receive ${message}`);
     }
     ['=='](other) {
       return dart.is(other, _NativeJsSendPort) && dart.notNull(dart.equals(this[_receivePort], dart.dload(other, _receivePort)));
     }
     get hashCode() {
       return this[_receivePort][_id];
     }
   }
   _NativeJsSendPort[dart.implements] = () => [isolate.SendPort];
   dart.setSignature(_NativeJsSendPort, {
@@ skipping 141 matching lines @@
   });
   let _once = Symbol('_once');
   let _inEventLoop = Symbol('_inEventLoop');
   let _handle = Symbol('_handle');
   class TimerImpl extends core.Object {
     TimerImpl(milliseconds, callback) {
       this[_once] = true;
       this[_inEventLoop] = false;
       this[_handle] = null;
       if (milliseconds == 0 && (!dart.notNull(hasTimer()) || dart.notNull(exports._globalState.isWorker))) {
-        let internalCallback = (() => {
+        let internalCallback = () => {
           this[_handle] = null;
           callback();
-        }).bind(this);
+        };
         dart.fn(internalCallback, dart.void, []);
         this[_handle] = 1;
         exports._globalState.topEventLoop.enqueue(exports._globalState.currentContext, internalCallback, 'timer');
         this[_inEventLoop] = true;
       } else if (hasTimer()) {
-        let internalCallback = (() => {
+        let internalCallback = () => {
           this[_handle] = null;
           leaveJsAsync();
           callback();
-        }).bind(this);
+        };
         dart.fn(internalCallback, dart.void, []);
         enterJsAsync();
         this[_handle] = self.setTimeout(_js_helper.convertDartClosureToJS(internalCallback, 0), milliseconds);
       } else {
         dart.assert(dart.notNull(milliseconds) > 0);
         throw new core.UnsupportedError("Timer greater than 0.");
       }
     }
     periodic(milliseconds, callback) {
       this[_once] = false;
       this[_inEventLoop] = false;
       this[_handle] = null;
       if (hasTimer()) {
         enterJsAsync();
-        this[_handle] = self.setInterval(_js_helper.convertDartClosureToJS(dart.fn((() => {
+        this[_handle] = self.setInterval(_js_helper.convertDartClosureToJS(dart.fn(() => {
           callback(this);
-        }).bind(this)), 0), milliseconds);
+        }), 0), milliseconds);
       } else {
         throw new core.UnsupportedError("Periodic timer.");
       }
     }
     cancel() {
       if (hasTimer()) {
         if (this[_inEventLoop]) {
           throw new core.UnsupportedError("Timer in event loop cannot be canceled.");
         }
         if (this[_handle] == null)
@@ skipping 68 matching lines @@
   exports.leaveJsAsync = leaveJsAsync;
   exports.isWorker = isWorker;
   exports.startRootIsolate = startRootIsolate;
   exports.IsolateNatives = IsolateNatives;
   exports.RawReceivePortImpl = RawReceivePortImpl;
   exports.ReceivePortImpl = ReceivePortImpl;
   exports.TimerImpl = TimerImpl;
   exports.hasTimer = hasTimer;
   exports.CapabilityImpl = CapabilityImpl;
 })(_isolate_helper, core, _native_typed_data, _interceptors, _js_helper, isolate, _foreign_helper, _js_embedded_names, collection, async);