refactor(material/core): post migration fixup

Author: crisbeto

src/material/core/theming/_theming.scss

@@ -109,10 +109,10 @@ $_mat-theme-emitted-density: () !default;
   @return (
     primary: $primary,
     accent: $accent,
-    warn: if($warn != null, $warn, palette(palette.$red)),
+    warn: if($warn != null, $warn, palette(palette.$mat-red)),
     is-dark: false,
-    foreground: palette.$light-theme-foreground,
-    background: palette.$light-theme-background,
+    foreground: palette.$mat-light-theme-foreground,
+    background: palette.$mat-light-theme-background,
   );
 }
 
@@ -122,17 +122,17 @@ $_mat-theme-emitted-density: () !default;
   @return (
     primary: $primary,
     accent: $accent,
-    warn: if($warn != null, $warn, palette(palette.$red)),
+    warn: if($warn != null, $warn, palette(palette.$mat-red)),
     is-dark: true,
-    foreground: palette.$dark-theme-foreground,
-    background: palette.$dark-theme-background,
+    foreground: palette.$mat-dark-theme-foreground,
+    background: palette.$mat-dark-theme-background,
   );
 }
 
 // Creates a container object for a light theme to be given to individual component theme mixins.
 // TODO: Remove legacy API and rename `$primary` to `$config`. Currently it cannot be renamed
 // as it would break existing apps that set the parameter by name.
-@function light-theme($primary, $accent: null, $warn: palette(palette.$red)) {
+@function light-theme($primary, $accent: null, $warn: palette(palette.$mat-red)) {
   // This function creates a container object for the individual component theme mixins. Consumers
   // can construct such an object by calling this function, or by building the object manually.
   // There are two possible ways to invoke this function in order to create such an object:
@@ -169,7 +169,7 @@ $_mat-theme-emitted-density: () !default;
 // Creates a container object for a dark theme to be given to individual component theme mixins.
 // TODO: Remove legacy API and rename `$primary` to `$config`. Currently it cannot be renamed
 // as it would break existing apps that set the parameter by name.
-@function dark-theme($primary, $accent: null, $warn: palette(palette.$red)) {
+@function dark-theme($primary, $accent: null, $warn: palette(palette.$mat-red)) {
   // This function creates a container object for the individual component theme mixins. Consumers
   // can construct such an object by calling this function, or by building the object manually.
   // There are two possible ways to invoke this function in order to create such an object:
@@ -339,15 +339,14 @@ $_mat-theme-emitted-density: () !default;
   // styles **once** and at root. This matches the old behavior where density styles were
   // part of the base component styles (that did not use view encapsulation).
   // TODO: Remove this compatibility logic when the legacy theming API is removed.
-  $mat-private-density-generate-at-root: is-legacy-constructed-theme($theme);
-  $mat-private-density-generate-styles: not $duplicate-legacy-density;
+  compatibility.$density-generate-at-root: is-legacy-constructed-theme($theme);
+  compatibility.$density-generate-styles: not $duplicate-legacy-density;
 
   @content;
   $theme-ignore-duplication-warnings: $orig-mat-theme-ignore-duplication-warnings !global;
 
-  // TODO: after the migration is finished, these need to refer to the `compatibility` import.
-  $mat-private-density-generate-at-root: false;
-  $mat-private-density-generate-styles: true;
+  compatibility.$density-generate-at-root: false;
+  compatibility.$density-generate-styles: true;
 }
 
 // Checks whether the given value resolves to a theme object. Theme objects are always