Change TypeMask.base to be a ClassElement.

sdk/lib/_internal/compiler/implementation/universe/universe.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.
 
 library universe;
 
 import '../elements/elements.dart';
 import '../dart2jslib.dart';
 import '../dart_types.dart';
 import '../types/types.dart';
@@ skipping 620 matching lines @@
     Map<TypeMask, TypedSelector> map = canonicalizedValues.putIfAbsent(untyped,
         () => new Map<TypeMask, TypedSelector>());
     TypedSelector result = map[mask];
     if (result == null) {
       int hashCode = Selector.mixHashCodeBits(untyped.hashCode, mask.hashCode);
       result = map[mask] = new TypedSelector.internal(mask, untyped, hashCode);
     }
     return result;
   }
 
-  factory TypedSelector.exact(DartType base, Selector selector)
+  factory TypedSelector.exact(ClassElement base, Selector selector)
       => new TypedSelector(new TypeMask.exact(base), selector);
 
-  factory TypedSelector.subclass(DartType base, Selector selector)
+  factory TypedSelector.subclass(ClassElement base, Selector selector)
       => new TypedSelector(new TypeMask.subclass(base), selector);
 
-  factory TypedSelector.subtype(DartType base, Selector selector)
+  factory TypedSelector.subtype(ClassElement base, Selector selector)
       => new TypedSelector(new TypeMask.subtype(base), selector);
 
   bool appliesUnnamed(Element element, Compiler compiler) {
     assert(sameNameHack(element, compiler));
     // [TypedSelector] are only used after resolution.
     assert(compiler.phase > Compiler.PHASE_RESOLVING);
     if (!element.isMember()) return false;
 
     // A closure can be called through any typed selector:
     // class A {
     //   get foo => () => 42;
     //   bar() => foo(); // The call to 'foo' is a typed selector.
     // }
     if (element.getEnclosingClass().isClosure()) {
       return appliesUntyped(element, compiler);
     }
 
     if (!mask.canHit(element, this, compiler)) return false;
     return appliesUntyped(element, compiler);
   }
 }