FloatingActionButton and ThemeData's accent properties

Summary

Context

Description of change

Migration guide

Timeline

References

Summary

Removed Flutter’s FloatingActionButton (FAB) dependency on
ThemeData accent properties.

Context

This was a small part of the Material Theme System Updates project.

Previously, the ThemeData accentIconTheme property was only
used by FloatingActionButton to determine the default
color of the text or icons that appeared within the button.

FloatingActionButton also used the
ThemeData accentTextTheme property,
however this dependency was undocumented and unnecessary.