Chrome Version:52.0.2715.0 (Official Build)3fae42f136f929251b627b2ae6300100afc8ab83-refs/heads/master@{#388964} 32/64 bit
OS: Windows (7, 8, 10), Mac (10.10.5)(10.11.4),Linux (ubuntu 14.04 LTS)

What steps will reproduce the problem?
1. Launch chrome, any navigate to any youtube video and Click on ‘Fullscreen’ icon ,then click on ‘Allow’ 
2. Go the chrome://md-settings/siteSettings/all ,click on link for detail and change the exception to ‘Block’ 
3. Navigate to chrome://settings/contentExceptions#fullscreen and observe

Actual: Two entries are seen in chrome://settings/contentExceptions#fullscreen for the same video.
Expected: No such entry should be seen for same video.

This is regression issue, broken in ‘M 51’ and will soon update the bisect info:

 

Deleted: actual_full.mov 5.1 MB

actual_full.mov 5.1 MB Download

Deleted: Exp_full.mov 9.0 MB

Exp_full.mov 9.0 MB Download