Make sure required type arguments are given when using factories.

sdk/lib/_internal/compiler/implementation/enqueue.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart2js;
 
 class EnqueueTask extends CompilerTask {
   final ResolutionEnqueuer resolution;
   final CodegenEnqueuer codegen;
 
@@ skipping 368 matching lines @@
   void registerIsCheck(DartType type, TreeElements elements) {
     // Even in checked mode, type annotations for return type and argument
     // types do not imply type checks, so there should never be a check
     // against the type variable of a typedef.
     assert(type.kind != TypeKind.TYPE_VARIABLE ||
            !type.element.enclosingElement.isTypedef());
     universe.isChecks.add(type);
     compiler.backend.registerIsCheck(type, this, elements);
   }
 
+  /**
+   * If a factory constructor is used with type arguments, we lose track
+   * which arguments could be used to create instances of classes that use their
+   * type variables as expressions, so we have to remember if we saw such a use.
+   */
+  void registerFactoryWithTypeArguments(TreeElements elements) {
+    universe.usingFactoryWithTypeArguments = true;
+  }
+
   void registerAsCheck(DartType type, TreeElements elements) {
     registerIsCheck(type, elements);
     compiler.backend.registerAsCheck(type, elements);
   }
 
   void forEach(f(WorkItem work));
 
   void logSummary(log(message)) {
     _logSpecificSummary(log);
     nativeEnqueuer.logSummary(log);
@@ skipping 164 matching lines @@
     while(!queue.isEmpty) {
       // TODO(johnniwinther): Find an optimal process order for codegen.
       f(queue.removeLast());
     }
   }
 
   void _logSpecificSummary(log(message)) {
     log('Compiled ${generatedCode.length} methods.');
   }
 }