Bugzilla

**Affected versions**
* 75.0a1 (2020-02-27)
* 74.0b8
* 73.0

**Affected platforms**
* Windows 10
* macOS 10.15
* Ubuntu 18.04

**Steps to reproduce**
1. Open any site
2. Click on the Star icon inside the address bar
3. Expand the folder section
4. Create a new folder and rename it with a long title (that extends the visible input area)
5. Attempt to create a new folder 

**Expected result**
* The New Folder input field keeps its default size

**Actual result**
* The New Folder input field increases its width

**Regression range**
* First bad:  b0124f06562982dce60b820d95aad23afd5cec90
* Last good: 1e64b8a0c546a49459d404aaf930d5b1f621246a
* Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=1e64b8a0c546a49459d404aaf930d5b1f621246a&tochange=b0124f06562982dce60b820d95aad23afd5cec90

**Additional notes**
*  The scrollbar (when enabled) is already overlapped only by clicking the New folder button, but with the steps mentioned above the input field is way out of bound (see the screenshot)

**Affected versions**
* 75.0a1 (2020-02-25)
* 74.0b8
* 73.0

**Affected platforms**
* Windows 10
* macOS 10.15
* Ubuntu 18.04

**Steps to reproduce**
1. Open any site
2. Click on the Star icon inside the address bar
3. Expand the folder section
4. Create a new folder and rename it with a long title (that extends the visible input area)
5. Attempt to create a new folder 

**Expected result**
* The New Folder input field keeps its default size

**Actual result**
* The New Folder input field increases its width

**Regression range**
* First bad:  b0124f06562982dce60b820d95aad23afd5cec90
* Last good: 1e64b8a0c546a49459d404aaf930d5b1f621246a
* Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=1e64b8a0c546a49459d404aaf930d5b1f621246a&tochange=b0124f06562982dce60b820d95aad23afd5cec90

**Additional notes**
*  The scrollbar (when enabled) is already overlapped only by clicking the New folder button, but with the steps mentioned above the input field is way out of bound (see the screenshot)