bug(theming): There is no way to read density scale from theme

[shhdharmen]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

18

Description

In Angular Material 18, developers could use Angular Material's theme's density scale, so that their custom components aligns with other Angular Material components.

In v18, developers could use mat.get-theme-density($theme); to get the scale. Link to docs.

In v19, it's not clear how to get density scale from theme.

Reproduction

Not needed.

Expected Behavior

Developers should be able to read density scale in Angular Material 19.

Actual Behavior

Developers are not able to read density scale in Angular Material 19.

Environment

• Angular: 19
• CDK/Material: 19
• Browser(s): Edge
• Operating System (e.g. Windows, macOS, Ubuntu): Windows