The "Tracking Protection" doorhanger is wrongly dismissed when its margins are clicked

[Softvision-MariusComan]

[Affected Versions]:

• Unbranded Firefox Beta (59.0b14) Build ID:20180301022608

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Prerequisites]:

• Have a new Firefox profile.
• Have the following prefs. in the "about:config" page (If a preference does not exist, please create it):
  • “extensions.legacy.enabled” pref set to “true”;
  • “xpinstall.signatures.required” pref set to “false”;
  • “extensions.tracking_protection_messaging_study.variation_override” pref set to "fast".
• Have the latest "Tracking Protection Messaging Shield Study" add-on (1.0.3) installed.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites and navigate to any website.
2. Click the the "pageAction Badge" from the right part of the sidebar (if the doorhanger is not already displayed).
3. Press the "Keep Protecting Me" button and click on the "pageAction Badge" again.
4. Move the mouse cursor over any of the doorhanger's margins until it is changed into a "Link Select" pointer.
5. Left click and observe the behavior.

[Expected result]:

• Nothing happens.

[Actual result]:

• The doorhanger is dismissed.

[Notes]:

• The issue is also reproducible with the “extensions.tracking_protection_messaging_study.variation_override” pref set to "private".
• The issue is not reproducible on the intro panel.
• Attached a screen recording of the issue:

[biancadanforth]

Thanks Marius for finding this. Since this panel is readily available to be re-opened on any http(s) page on pageAction button click, I'm not too concerned about this "edge" case (pun). That is weird though. I'm thinking this is a P3.