Format all dart dev compiler files

pkg/dev_compiler/test/js/builder_test.dart

 import 'package:dev_compiler/src/js_ast/js_ast.dart';
 import 'package:test/test.dart';
 
 final _prenumberedPlaceholders = new RegExp(r'#\d+');
 
 _parser(String src) =>
     new MiniJsParser(src.replaceAll(_prenumberedPlaceholders, '#'));
 
 _check(Node node, String expected) =>
     expect(node.toString(), 'js_ast `$expected`');
 
-_checkStatement(String src) =>
-    _check(_parser(src).parseStatement(), src);
+_checkStatement(String src) => _check(_parser(src).parseStatement(), src);
 
-_checkExpression(String src) =>
-    _check(_parser(src).parseExpression(), src);
+_checkExpression(String src) => _check(_parser(src).parseExpression(), src);
 
 main() {
   group('MiniJsParser', () {
     // TODO(ochafik): Add more coverage.
     test('parses classes with complex members', () {
-      _checkExpression(
-          'class Foo {\n'
+      _checkExpression('class Foo {\n'
           '  [foo](...args) {}\n'
           '  [#0](x) {}\n'
           '  static [foo](...args) {}\n'
           '  static [#1](x) {}\n'
           '  get [foo]() {}\n'
           '  get [#2]() {}\n'
           '  static get [foo]() {}\n'
           '  static get [#3]() {}\n'
           '  set [foo](v) {}\n'
           '  set [#4](v) {}\n'
           '  static set [foo](v) {}\n'
           '  static set [#5](v) {}\n'
           '}');
     });
     test('parses statements', () {
       _checkStatement('for (let i = 0; i < 10; i++) {\n}\n');
       _checkStatement('for (let i = 0, j = 1; i < 10; i++) {\n}\n');
       _checkStatement('var [x, y = []] = list;\n');
       _checkStatement('var {x, y = {x: y}} = obj;\n');
     });
   });
 }