Allow ambiguous Expect and ExpectException imports.

sdk/lib/_internal/compiler/implementation/elements/modelx.dart

 // Copyright (c) 2013, 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.
 
 library elements.modelx;
 
 import 'dart:uri';
 
 import 'elements.dart';
 import '../../compiler.dart' as api;
@@ skipping 582 matching lines @@
   /**
    * Adds [element] to the import scope of this library.
    *
    * If an element by the same name is already in the imported scope, an
    * [ErroneousElement] will be put in the imported scope, allowing for the
    * detection of ambiguous uses of imported names.
    */
   void addImport(Element element, DiagnosticListener listener) {
     Element existing = importScope[element.name];
     if (existing != null) {
+      // TODO(8474): Remove the "Expect" special casing.
+      if (element.name == const SourceString("Expect") ||
+          element.name == const SourceString("ExpectException")) {
+        return;
+      }
       // TODO(johnniwinther): Provide access to the import tags from which
       // the elements came.
       importScope[element.name] = new AmbiguousElementX(
           MessageKind.DUPLICATE_IMPORT, {'name': element.name},
           this, existing, element);
     } else {
       importScope[element.name] = element;
     }
   }
 
@@ skipping 1359 matching lines @@
 
   MetadataAnnotation ensureResolved(Compiler compiler) {
     if (resolutionState == STATE_NOT_STARTED) {
       compiler.resolver.resolveMetadataAnnotation(this);
     }
     return this;
   }
 
   String toString() => 'MetadataAnnotation($value, $resolutionState)';
 }