Check in codegen test expectations.

test/codegen/expect/language/generic_field_mixin2_test.js

+dart_library.library('language/generic_field_mixin2_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__generic_field_mixin2_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const generic_field_mixin2_test = Object.create(null);
+  let M = () => (M = dart.constFn(generic_field_mixin2_test.M$()))();
+  let A = () => (A = dart.constFn(generic_field_mixin2_test.A$()))();
+  let C1 = () => (C1 = dart.constFn(generic_field_mixin2_test.C1$()))();
+  let C1Ofint = () => (C1Ofint = dart.constFn(generic_field_mixin2_test.C1$(core.int)))();
+  let C1OfString = () => (C1OfString = dart.constFn(generic_field_mixin2_test.C1$(core.String)))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  generic_field_mixin2_test.M$ = dart.generic(T => {
+    class M extends core.Object {
+      new() {
+        this.field = dart.wrapType(T);
+      }
+    }
+    dart.addTypeTests(M);
+    return M;
+  });
+  generic_field_mixin2_test.M = M();
+  generic_field_mixin2_test.A$ = dart.generic(U => {
+    class A extends core.Object {}
+    dart.addTypeTests(A);
+    return A;
+  });
+  generic_field_mixin2_test.A = A();
+  generic_field_mixin2_test.C1$ = dart.generic(V => {
+    class C1 extends dart.mixin(core.Object, generic_field_mixin2_test.M$(V)) {}
+    return C1;
+  });
+  generic_field_mixin2_test.C1 = C1();
+  generic_field_mixin2_test.C2 = class C2 extends dart.mixin(core.Object, generic_field_mixin2_test.M$(core.int)) {};
+  generic_field_mixin2_test.C3 = class C3 extends dart.mixin(core.Object, generic_field_mixin2_test.M$(core.String)) {};
+  generic_field_mixin2_test.main = function() {
+    expect$.Expect.equals(dart.wrapType(core.int), new (C1Ofint())().field);
+    expect$.Expect.equals(dart.wrapType(core.String), new (C1OfString())().field);
+    expect$.Expect.equals(dart.wrapType(core.int), new generic_field_mixin2_test.C2().field);
+    expect$.Expect.equals(dart.wrapType(core.String), new generic_field_mixin2_test.C3().field);
+  };
+  dart.fn(generic_field_mixin2_test.main, VoidTodynamic());
+  // Exports:
+  exports.generic_field_mixin2_test = generic_field_mixin2_test;
+});