Use short array syntax in method signatures

test/codegen/expect/BenchmarkBase.js

 var BenchmarkBase = dart.defineLibrary(BenchmarkBase, {});
 var core = dart.import(core);
 (function(exports, core) {
   'use strict';
   class Expect extends core.Object {
     static equals(expected, actual) {
       if (!dart.equals(expected, actual)) {
         throw `Values not equal: ${expected} vs ${actual}`;
       }
     }
     static listEquals(expected, actual) {
       if (expected[core.$length] != actual[core.$length]) {
         throw `Lists have different lengths: ${expected[core.$length]} vs ${actual[core.$length]}`;
       }
       for (let i = 0; dart.notNull(i) < dart.notNull(actual[core.$length]); i = dart.notNull(i) + 1) {
         Expect.equals(expected[core.$get](i), actual[core.$get](i));
       }
     }
     fail(message) {
       throw message;
     }
   }
   dart.setSignature(Expect, {
-    methods: () => ({fail: dart.functionType(dart.dynamic, [dart.dynamic])}),
+    methods: () => ({fail: [dart.dynamic, [dart.dynamic]]}),
     statics: () => ({
-      equals: dart.functionType(dart.void, [dart.dynamic, dart.dynamic]),
-      listEquals: dart.functionType(dart.void, [core.List, core.List])
+      equals: [dart.void, [dart.dynamic, dart.dynamic]],
+      listEquals: [dart.void, [core.List, core.List]]
     }),
     names: ['equals', 'listEquals']
   });
   class BenchmarkBase extends core.Object {
     BenchmarkBase(name) {
       this.name = name;
     }
     run() {}
     warmup() {
       this.run();
@@ skipping 29 matching lines @@
       this.teardown();
       return result;
     }
     report() {
       let score = this.measure();
       core.print(`${this.name}(RunTime): ${score} us.`);
     }
   }
   dart.setSignature(BenchmarkBase, {
     methods: () => ({
-      run: dart.functionType(dart.void, []),
-      warmup: dart.functionType(dart.void, []),
-      exercise: dart.functionType(dart.void, []),
-      setup: dart.functionType(dart.void, []),
-      teardown: dart.functionType(dart.void, []),
-      measure: dart.functionType(core.double, []),
-      report: dart.functionType(dart.void, [])
+      run: [dart.void, []],
+      warmup: [dart.void, []],
+      exercise: [dart.void, []],
+      setup: [dart.void, []],
+      teardown: [dart.void, []],
+      measure: [core.double, []],
+      report: [dart.void, []]
     }),
-    statics: () => ({measureFor: dart.functionType(core.double, [core.Function, core.int])}),
+    statics: () => ({measureFor: [core.double, [core.Function, core.int]]}),
     names: ['measureFor']
   });
   // Exports:
   exports.Expect = Expect;
   exports.BenchmarkBase = BenchmarkBase;
 })(BenchmarkBase, core);