fix language_tests.js to use strict mode

karma.conf.js

 // Karma configuration
 // Generated on Mon Apr 20 2015 06:33:20 GMT-0700 (PDT)
 
 module.exports = function(config) {
   var harmony_flags = '--js-flags="' + [
     '--harmony',
   ].join(' ') + '"';
 
   var configuration = {
 
@@ skipping 41 matching lines @@
     reporters: ['progress'],
 
     // web server port
     port: 9876,
 
     // enable / disable colors in the output (reporters and logs)
     colors: true,
 
     // level of logging
     // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
-    logLevel: config.LOG_DEBUG,
+    logLevel: config.LOG_INFO,
 
     // enable / disable watching file and executing tests whenever any file changes
     autoWatch: true,
 
     // start these browsers
     // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
 
     // FIXME(vsm): Once harmony is on by default, we can simply add the following:
     //   browsers: ['Chrome'],
     // and remove the custom launchers.
     customLaunchers: {
       chrome_harmony: {
-        base: 'Chrome',
+        base: 'Chrome',
         flags: [ harmony_flags ],
       },
 
       chrome_canary_harmony: {
-        base: 'ChromeCanary',
+        base: 'ChromeCanary',
         flags: [ harmony_flags ],
       },
 
       chrome_canary_travis: {
-        base: 'ChromeCanary',
+        base: 'ChromeCanary',
         flags: [ '--no-sandbox', harmony_flags ]
       },
     },
     browsers: ['chrome_canary_harmony'],
 
     // Continuous Integration mode
     // if true, Karma captures browsers, runs the tests and exits
     singleRun: false,
   };
 
   if (process.env.TRAVIS) {
     configuration.browsers = ['chrome_canary_travis'];
     configuration.autoWatch = false;
+    configuration.logLevel = config.LOG_DEBUG;
   }
 
   config.set(configuration);
 };