It seems a lot of content_browsertests on the Jelly Bean Tester have been failing from build #6021:

https://uberchromegw.corp.google.com/i/chromium.android/builders/Jelly%20Bean%20Tester/builds/6021

and onwards.

Not sure how to debug this - I don't see any differences between the logs of build 6020 and 6021 :/

Could we take a look at the actual device maybe?