Cast extension updates - every loaded sender app enters broken state

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Load up a YouTube video
2. Open up background page of Google Cast extension
3. Run chrome.runtime.onUpdateAvailable.dispatch()
4. Attempt to cast YouTube

Expected:
Youtube app should start on Chromecast and the video should begin playing

Actual:
Cast button on player does nothing, clicking Cast extension and choosing 
Chromecast causes a Tab cast instead

Systems:
Tested on Windows and Mac

Additional Information:
Our app (Videostream) has a spike in support tickets and users having issues 
casting our app every time there is a cast extension update. We've noticed this 
spike twice in a row: June 23rd, and now July 8th.

The current cast extension seems to have been updated yesterday (15.623.0.4) - 
presumably this is a minor update as it is still dated for June 23rd.

Original issue reported on code.google.com by gra...@kennery.com on 8 Jul 2015 at 6:41

[GoogleCodeExporter]

Our TAM should have already contacted you on the best way to handle this issue. 
Closing the ticket.

Original comment by jonathan...@google.com on 9 Jul 2015 at 8:13

• Changed state: NotSDK