Reland support for firefox jsshell.

tools/testing/dart/test_options.dart

Index: tools/testing/dart/test_options.dart
===================================================================
--- tools/testing/dart/test_options.dart	(revision 13274)
+++ tools/testing/dart/test_options.dart	(working copy)
@@ -88,6 +88,8 @@
 
     d8: Run JavaScript from the command line using v8.
 
+    jsshell: Run JavaScript from the command line using firefox js-shell.
+
     drt: Run Dart or JavaScript in the headless version of Chrome,
          DumpRenderTree.
 
@@ -99,8 +101,8 @@
     none: No runtime, compile only (for example, used for dartc static analysis
           tests).''',
               ['-r', '--runtime'],
-              ['vm', 'd8', 'drt', 'dartium', 'ff', 'firefox', 'chrome',
-              'safari', 'ie', 'opera', 'none'],
+              ['vm', 'd8', 'jsshell', 'drt', 'dartium', 'ff', 'firefox',
+               'chrome', 'safari', 'ie', 'opera', 'none'],
               'vm'),
           new _TestOptionSpecification(
               'arch',
@@ -395,7 +397,7 @@
         // runs test.py -c dart2js -r drt,none the dart2js_none and
         // dart2js_drt will be duplicating work. If later we don't need 'none'
         // with dart2js, we should remove it from here.
-        validRuntimes = const ['d8', 'drt', 'none', 'dartium',
+        validRuntimes = const ['d8', 'jsshell', 'drt', 'none', 'dartium',
                                'ff', 'chrome', 'safari', 'ie', 'opera'];
         break;
       case 'dartc':
@@ -473,10 +475,11 @@
       configuration['runtime'] == 'ff';
     }
 
-    if (TestUtils.isBrowserRuntime(runtime)) {
-      configuration['browser'] = true;
-    }
+    configuration['browser'] = TestUtils.isBrowserRuntime(runtime);
 
+    // Set the javascript command line flag for less verbose status files.
+    configuration['jscl'] = TestUtils.isJsCommandLineRuntime(runtime);
+
     // Expand the test selectors into a suite name and a simple
     // regular expressions to be used on the full path of a test file
     // in that test suite. If no selectors are explicitly given use