Testing support for FF and Safari

pkg/dev_compiler/karma.conf.js

 // Karma configuration
 // Generated on Mon Apr 20 2015 06:33:20 GMT-0700 (PDT)
 
 module.exports = function(config) {
   var configuration = {
 
     // base path that will be used to resolve all patterns (eg. files, exclude)
     basePath: '',
 
     // frameworks to use
@@ skipping 71 matching lines @@
 
   if (process.env.TRAVIS) {
     configuration.browsers = ['chrome_canary_travis'];
     configuration.autoWatch = false;
     // Enable this for more logging on Travis.  It is too much for Travis to
     // automatically display, but still results in a downloadable raw log.
     // configuration.logLevel = config.LOG_DEBUG;
     configuration.client.captureConsole = true;
   }
 
+  if (process.env.DDC_BROWSERS) {
+    configuration.browsers = process.env.DDC_BROWSERS.split(':');
+  }
+
   config.set(configuration);
 };