Implement CHA through type mask and TypedSelector in the simple type inferrer.

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 '../closure.dart';
 import '../elements/elements.dart';
 import '../dart2jslib.dart';
 import '../dart_types.dart';
@@ skipping 466 matching lines @@
   /**
    * Check if [element] will be the one used at runtime when being
    * invoked on an instance of [cls].
    */
   bool hasElementIn(ClassElement cls, Element element) {
     return cls.lookupSelector(this) == element;
   }
 
   bool appliesUnnamed(Element element, Compiler compiler) {
     assert(sameNameHack(element, compiler));
-    // [TypedSelector] are only used when compiling.
-    assert(compiler.phase == Compiler.PHASE_COMPILING);
+    // [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.
     // }
     ClassElement other = element.getEnclosingClass();
     if (identical(other.superclass, compiler.closureClass)) {
       return appliesUntyped(element, compiler);
@@ skipping 31 matching lines @@
       ClassElement cls = self;
       if (cls.isSubclassOf(other)) {
         // Resolve an invocation of [element.name] on [self]. If it
         // is found, this selector is a candidate.
         return hasElementIn(cls, element) && appliesUntyped(element, compiler);
       }
     }
     return false;
   }
 }