Use Chrome for Protractor E2E testing.

This reverts to using Chrome with direct connect for E2E tests,
as build nodes should already have a configured virtual X server
for npm jobs. This also removes the need for Selenium, which
should speed up environment setup.

PhantomJS appears to be somewhat unreliable for E2E testing, and
does not allow for some extra features, such as reading from
browser console logs.

Change-Id: I77a4fa86469c96af5494dc8118217d47abbc6dea

test/protractor.conf.js

@@ -10,9 +10,10 @@ exports.config = {
 
   baseUrl: 'http://localhost:' + gulpConfig.serverPort + '/',
 
+  directConnect: true,
+
   capabilities: {
-    browserName: 'phantomjs',
-    'phantomjs.binary.path': phantomjs.path
+    browserName: 'chrome'
   },
 
   framework: 'jasmine',