Fix safari browser to use Future.value

tools/testing/dart/test_runner.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.
 
 /**
  * Classes and methods for executing tests.
  *
  * This module includes:
  * - Managing parallel execution of tests, including timeout checks.
  * - Evaluating the output of each test as pass/fail/crash/timeout.
@@ skipping 966 matching lines @@
 
 /** Modifies the --timeout=XX parameter passed to run_selenium.py */
 List<String> _modifySeleniumTimeout(List<String> arguments, int timeout) {
   return arguments.map((argument) {
     if (argument.startsWith('--timeout=')) {
       return "--timeout=$timeout";
     } else {
       return argument;
     }
   }).toList();
-  return;
 }
 
 
 /**
  * A RunningProcess actually runs a test, getting the command lines from
  * its [TestCase], starting the test process (and first, a compilation
  * process if the TestCase is a [BrowserTestCase]), creating a timeout
  * timer, and recording the results in a new [CommandOutput] object, which it
  * attaches to the TestCase.  The lifetime of the RunningProcess is limited
  * to the time it takes to start the process, run the process, and record
@@ skipping 202 matching lines @@
                                     testCase.timeout);
     _process.stdin.write(line);
     _stdoutSubscription.resume();
     _stderrSubscription.resume();
     Future.wait([_stdoutCompleter.future,
                  _stderrCompleter.future]).then((_) => _reportResult());
   }
 
   String _createArgumentsLine(List<String> arguments, int timeout) {
     arguments = _modifySeleniumTimeout(arguments, timeout);
-    return arguments.join(' ').concat('\n');
+    return arguments.join(' ') + '\n';
   }
 
   void _reportResult() {
     if (!active) return;
     // _status == '>>> TEST {PASS, FAIL, OK, CRASH, FAIL, TIMEOUT}'
 
     var outcome = _status.split(" ")[2];
     var exitCode = 0;
     if (outcome == "CRASH") exitCode = CRASHING_BROWSER_EXITCODE;
     if (outcome == "FAIL" || outcome == "TIMEOUT") exitCode = 1;
@@ skipping 534 matching lines @@
                                test.usesWebDriver &&
                                !test.configuration['noBatch'];
       if (useBatchRunnerForAnalyzer || isWebdriverCommand) {
         TestCaseEvent oldCallback = test.completedHandler;
         void testCompleted(TestCase test_arg) {
           _numProcesses--;
           if (isBrowserCommand) {
             _numBrowserProcesses--;
           }
           eventFinishedTestCase(test_arg);
-          if (test_arg is BrowserTestCase) test_arg.notifyObservers();
+          if (test_arg is BrowserTestCase) {
+            (test_arg as BrowserTestCase).notifyObservers();
+          }
           oldCallback(test_arg);
           _tryRunTest();
         };
         test.completedHandler = testCompleted;
         if (test.usesBrowserController) {
           _startBrowserControllerTest(test);
         } else {
           _getBatchRunner(test).startTest(test);
         }
       } else {
         // Once we've actually failed a test, technically, we wouldn't need to
         // bother retrying any subsequent tests since the bot is already red.
         // However, we continue to retry tests until we have actually failed
         // four tests (arbitrarily chosen) for more debugable output, so that
         // the developer doesn't waste his or her time trying to fix a bunch of
         // tests that appear to be broken but were actually just flakes that
         // didn't get retried because there had already been one failure.
         bool allowRetry = _MAX_FAILED_NO_RETRY > _numFailedTests;
         runNextCommandWithRetries(test, allowRetry).then((TestCase testCase) {
           _numProcesses--;
           if (isBrowserCommand) {
             _numBrowserProcesses--;
           }
           if (isTestCaseFinished(testCase)) {
             testCase.completed();
             eventFinishedTestCase(testCase);
-            if (testCase is BrowserTestCase) testCase.notifyObservers();
+            if (testCase is BrowserTestCase) {
+              (testCase as BrowserTestCase).notifyObservers();
+            }
           } else {
             _tests.addFirst(testCase);
           }
           _tryRunTest();
         });
       }
 
       _numProcesses++;
       if (isBrowserCommand) {
         _numBrowserProcesses++;
@@ skipping 107 matching lines @@
     }
   }
 
   void eventAllTestsDone() {
     for (var listener in _eventListener) {
       listener.allDone();
     }
   }
 }