Bugzilla

**Affected versions**
* 88.0a1(2021-03-03), 87.0b5

**Affected platforms**
* Windows 10 

**Steps to reproduce**
1. Launch Firefox, access the Customize page and add the Profiler tool to the overflow;
2. Click on the overflow button;
3. Click on the Profiler > to expand the settings section;
4. Observe then click the Settings picker dropdown button;

**Expected result**
* button is centered;

**Actual result**
* button is centered only after the click;

**Regression range**
* not a regression, issue was visible with initial implementation;
* First bad: 2020-03-25;
* Last good: 2020-03-24;
* Pushlog: [URL](https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=081cfce87dbe4ee41e6b56f925a292e5640e7e57&tochange=4695dbc761d726d1465b453df60482f77aa6b710)
* Potential regressor: bug 1572786;

**Additional notes**
* macOS 10.15 appears to not be affected;
* issue reproducible with OS recommended and 800x600 resolution;
* attached recording with the issue.

**Affected versions**
* 88.0a1(2021-03-03), 87.0b5

**Affected platforms**
* Windows 10 

**Steps to reproduce**
1. Launch Firefox, access the Customize page and add the Profiler tool to the overflow;
2. Click on the overflow button;
3. Click on the Profiler > to expand the settings section;
4. Observe then click the Settings picker dropdown button;

**Expected result**
* button is centered;

**Actual result**
* button is centered only after the click;
* max-length values might need revision as well to best fit in the section;

**Regression range**
* not a regression, issue was visible with initial implementation;
* First bad: 2020-03-25;
* Last good: 2020-03-24;
* Pushlog: [URL](https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=081cfce87dbe4ee41e6b56f925a292e5640e7e57&tochange=4695dbc761d726d1465b453df60482f77aa6b710)
* Potential regressor: bug 1572786;

**Additional notes**
* macOS 10.15 appears to not be affected;
* issue reproducible with OS recommended and 800x600 resolution;
* attached recording with the issue.