feature(launcher): aggregate failures at the end

Author: hankduan

lib/launcher.js

@@ -191,17 +191,22 @@ var reporter = {
   },
 
   reportSummary: function() {
+    var totalFailures = 0;
     this.taskReporters_.forEach(function(taskReporter) {
       var capability = taskReporter.task.capability;
       var shortName = (capability.browserName) ? capability.browserName : '';
       shortName += (capability.version) ? capability.version : '';
       shortName += (' #' + taskReporter.task.taskId);
       if (taskReporter.failedCount) {
         log_(shortName + ' failed ' + taskReporter.failedCount + ' test(s)');
+        totalFailures += taskReporter.failedCount;
       } else {
         log_(shortName + ' passed');
       }
     });
+    if (this.taskReporters_.length > 1 && totalFailures) {
+      log_('overall: ' + totalFailures + ' failure(s)');
+    }
   }
 };