v54.8.0

This new release introduces shapes support to buttons and a variety of new themer APIs for many
components.

New features

Buttons can now be styled with different shape outlines. Example usage:

MDCRectangleShapeGenerator *raisedShapeGenerator =
    [[MDCRectangleShapeGenerator alloc] init];
[raisedShapeGenerator setCorners:[[MDCCutCornerTreatment alloc] initWithCut:8.f]];
button.shapeGenerator = raisedShapeGenerator;

There is a new Text Button API for theming an MDCButton to make complete use of typography, color,
and other configurable properties of a button's design. A button themed as a text button is closely
equivalent to the MDCFlatButton class, MDCFlatButton will soon be deprecated as a result in
favor of the following pattern:

// Define your button's scheme somewhere centrally in your app.
let buttonScheme = MDCButtonScheme()
buttonScheme.colorScheme = myAppColorScheme

// Apply the button scheme to an MDCButton to give it the appearance of a text button.
// button: MDCButton
MDCTextButtonThemer.applyScheme(buttonScheme, to: button)

NavigationBar and FlexibleHeader now both have a surface variant themer.

Chips and Tabs have updated color themers.

API changes

Buttons

MDCButton

new property: shapeGenerator in MDCButton

Component changes

Tabs

Changes

• Fix crasher within tab example (#3370) (John Detloff)
• Update MDCTabBar color themer (#3361) (John Detloff)

Buttons

Changes

• Added Shapes Support (#3368) (Yarden Eitan)
• [Button] Color themer: Changed class of argument to be MDCButton rather than be a subclass. (#3382) (Randall Li)
• [Button] Created button themer that aggregates multiple subsystems to style buttons. (#3362) (Randall Li)

Chips

Changes

• color themer implementation. (#3372) (Mohammad Cazi)

NavigationBar

Changes

• Add surface variant theme. (#3376) (featherless)

FlexibleHeader

Changes

• Add a surface variant color themer API. (#3380) (featherless)