Affected versions

• 85.0b7, 85.0a1(2020-01-10);

Affected platforms

• Windows 7;

Steps to reproduce

1. Launch Firefox, enable Print preview;
2. Observe the Previous/Next Page buttons;

Expected result

• icon for buttons is not deformed, consistent across other OSs;

Actual result

• icons for prev.next page are small and deformed;

Regression range

• window is just for the icons being deformed, considered "good" builds that had them visible properly (even with the same styling for all 4 buttons);
• First bad: 2016-08-07;
• Last good: 2016-08-06;
• Pushlog: URL;

Additional notes

• attached screenshot to illustrate the issue;
• can compare with the caret from the [Shrink To Fit] button; fwiw, probably all the 4 page control buttons should use the same type.