Increase the timeout for the DomAutomationTest. They are the first tests in the browser test suite, and the slow cold start causes a lot of flakiness on the buildbot because those tests often take more than 20 seconds to finish. 
Increase the timeout for the DomAutomationTest. They are the first
tests in the browser test suite, and the slow cold start causes a lot of
flakiness on the buildbot because those tests often take more than 20 seconds
to finish. 

The code is inspired from PDFBrowserTest.Loading

BUG=61636
Review URL: http://codereview.chromium.org/6312026

git-svn-id: http://src.chromium.org/svn/trunk/src@73114 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 5df0ef69845b4439f0dcfc3ff420f8f89f3c2ffc
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser