Clearing browsing data will clear the block. We're also working on a patch that will allow you to clear the block by resetting the permission state to "Ask" via the page info dialog from the lock icon.

Sounds good, thanks! I cleared the block successfully by clearing the "Cookies and other site and plugin data" subtype.

Thanks for the bug report. Hopefully we'll have the extra clearing behaviour on Canary in the next week or so (and I'll updated the chromestatus entry when it lands so it's clear how to remove the block in testing). :)

+patricialor, who will possibly implement (it'll be me otherwise).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7131c1fee08ad62e85476acfd3604765bc997f39

commit 7131c1fee08ad62e85476acfd3604765bc997f39
Author: patricialor <patricialor@chromium.org>
Date: Fri Apr 07 01:25:52 2017

Permissions: Clear embargo if user changes an embargoed permission's setting.

Allow the embargo status of a permission to be cleared when the user changes the
setting for an embargoed permission to "Ask" or "Allow". However, the system
will still remember that the setting was previously embargoed, so if another
permission prompt is dismissed for that permission, it will be re-embargoed.
Permissions embargoed because they are blacklisted will be re-embargoed if they
are still on the blacklist during the next permission request.

BUG= 704771 
TEST=Run Chrome with the command line flag
--enable-features=BlockPromptsIfDismissedOften and navigate to
https://permission.site. Place the notification permission under embargo by
clicking the "Notifications" button three times until the permission prompt no
longer appears. In the page info bubble, the "Notifications" drop-down should
say "block". Choose "Allow" instead, which should update the bubble to allow
notifications and ask for the page to be reloaded. Then change the drop-down to
"Ask", which should also update the notifications permission back to "Ask".
Click the "Notifications" button on the page again and notice the permission
prompt to ask for notifications permission is shown again.

Review-Url: https://codereview.chromium.org/2790473004
Cr-Commit-Position: refs/heads/master@{#462733}

[modify] https://crrev.com/7131c1fee08ad62e85476acfd3604765bc997f39/chrome/browser/android/preferences/website_preference_bridge.cc
[modify] https://crrev.com/7131c1fee08ad62e85476acfd3604765bc997f39/chrome/browser/permissions/permission_decision_auto_blocker.cc
[modify] https://crrev.com/7131c1fee08ad62e85476acfd3604765bc997f39/chrome/browser/permissions/permission_decision_auto_blocker.h
[modify] https://crrev.com/7131c1fee08ad62e85476acfd3604765bc997f39/chrome/browser/permissions/permission_decision_auto_blocker_unittest.cc
[modify] https://crrev.com/7131c1fee08ad62e85476acfd3604765bc997f39/chrome/browser/ui/page_info/page_info.cc

The change in #c4 should have fixed this for Desktop and Android.

Tested the issue on Windows 10 using chrome version #59.0.3067.6 and Mac 10.12.3 and Ubuntu 14.04 using chrome version #59.0.3067.0(due to non-availability of chrome dev build #59.0.3067.6 for OS-Mac and OS-Linux) as per comment #4.

Attached a screen cast for reference.

Following are the steps followed to reproduce the issue.
------------
1. Ran Chrome with the command line flag --enable-features=BlockPromptsIfDismissedOften
2. Navigated to https://permission.site.
3. Clicked the "Notifications" button three times, but permission prompt did not disappear.
4. In the page info bubble, clicked "allow" button.
5. In chrome://settings/content, clicked "notifications" option in which "ask before sending(recommended)" option was by default enabled.
6. Refreshed the permissions page and clicked the "Notifications" button on the page again and did not observe any permission prompt asking for notifications permission.

patricialor@ - Could you please verify the screen cast and please let us know if anything missed from our side. 

Thanks...!!

Deleted: 704771.mp4 3.1 MB

	704771.mp4 3.1 MB View Download

Oops, sorry - thanks for checking this, the instructions I provided were not complete. Here's your repro steps amended to include everything:

1. Run Chrome with the command line flag --enable-features=BlockPromptsIfDismissedOften
2. Navigate to https://permission.site.
3. Click the "Notifications" button, observe the permission prompt appeared under the omnibox, then press escape to close it.
4. Repeat step #3. On the fourth click, the prompt will not appear again.
5. Open the page info bubble by clicking on the "Secure" text in the omnibox. Observe the notifications drop-down says "Block".
6. Change this to "Allow".
7. Reload the page as asked. Observe that clicking on the "Notifications" button again turns it green.
8. Open the page info bubble again, but this time change the notifications drop-down to "Ask".
9. Click the "Notifications" button again and observe the permission prompt appears again under the omnibox. After pressing escape to close it, clicking the "Notifications" button again should not show another prompt.