fix(ListWrapper): fix JS ListWrapper.remove()

modules/facade/src/collection.dart

@@ -101,9 +101,7 @@ class ListWrapper {
       list.remove(items[i]);
     }
   }
-  static remove(List list, item) {
-    list.remove(item);
-  }
+  static bool remove(List list, item) => list.remove(item);
   static void clear(List l) { l.clear(); }
   static String join(List l, String s) => l.join(s);
   static bool isEmpty(list) => list.isEmpty;

modules/facade/src/collection.es6

@@ -149,9 +149,13 @@ export class ListWrapper {
       list.splice(index, 1);
     }
   }
-  static remove(list, item) {
-    var index = list.indexOf(item);
-    list.splice(index, 1);
+  static remove(list, el): boolean {
+    var index = list.indexOf(el);
+    if (index > -1) {
+      list.splice(index, 1);
+      return true;
+    }
+    return false;
   }
   static clear(list) {
     list.splice(0, list.length);