feat(material/theming): extend-theme sass function

src/material/checkbox/_checkbox-theme.scss

@@ -102,6 +102,13 @@
  );
 }
 
+/// Returns a theme config with the given tokens overridden.
+/// @param {Map} $theme The material theme for an application.
+/// @param {Map} $overrides The token values to override in the theme.
+@function extend-theme($theme, $overrides: ()) {
+ @return token-utils.extend-theme($theme, checkbox, $overrides);
+}
+
 /// Outputs all (base, color, typography, and density) theme styles for the mat-checkbox.
 /// @param {Map} $theme The theme to generate styles for.
 /// @param {ArgList} Additional optional arguments (only supported for M3 themes):

src/material/core/tokens/_token-utils.scss

@@ -255,3 +255,33 @@ $_component-prefix: null;
  }
  }
 }
+
+/// Returns a theme config with the given tokens overridden.
+/// @param {Map} $theme The material theme for an application.
+/// @param {Map} $overrides The token values to override in the theme.
+@function extend-theme($theme, $component, $overrides: ()) {
+ $internals: _mat-theming-internals-do-not-access;
+
+ @each $system in (color, typography, density, base) {
+
+ $system-name: $system + '-tokens';
+ $namespaces: map.get($theme, $internals, $system-name);
+ @each $namespace, $tokens in $namespaces {
+
+ @if (list.nth($namespace, 2) == $component) {
+ $namespace-overrides: if(list.length($namespace) == 3,
+ map.get($overrides, list.nth($namespace, 3)),
+ $overrides);
+
+ @each $name, $value in $tokens {
+ $token: map.get($namespace-overrides, $name);
+ @if $token != null {
+ $theme: map.set($theme, $internals, $system-name, $namespace, $name, $token);
+ }
+ }
+ }
+ }
+ }
+
+ @return $theme;
+}