Protractor is a testing system for angular http://angular.github.io/protractor/#/
The setup of protractor tests are driven by the conf.js file. At the gist listed below there is an example conf.js that will work with CrossbrowserTesting.com
The capabilities object needs to include the extra information about which browser and operating system you are going to run on CrossbrowserTesting.com. You can get these constants from the example script on the Selenium page.
The other change is you must include your username/authkey in the capabilities object. Those two fields are called username and password respectively.
You can also test more than one browser at a time by using the multicapabilties, see this tutorial on the protractor tutorial.
Also see this example of what a conf.js should look like for multicapabilities. https://gist.github.com/tonetheman/5369e5e7f6cbd8d95e41
That example will run firefox32 and firefox31 on WinXPSP2 simultaneously. The simple todo-spec.js is herehttps://gist.github.com/tonetheman/7b1e4bc9a60377b304e6