Added exports for ContextualMenu getItemStyles and getItemClassNames …

…to v8 (microsoft#24484)

* Added exports for ContextualMenu getItemStyles and getItemClassNames

* yarn change

* Fixed param comment

* Update API.md

packages/office-ui-fabric-react/etc/office-ui-fabric-react.api.md

@@ -1355,6 +1355,14 @@ export const getCommandBarStyles: (props: ICommandBarStyleProps) => ICommandBarS
 // @public (undocumented)
 export const getCommandButtonStyles: (customStyles: IButtonStyles | undefined) => IButtonStyles;
 
+// Warning: (ae-internal-missing-underscore) The name "getContextualMenuItemClassNames" should be prefixed with an underscore because the declaration is marked as @internal
+//
+// @internal @deprecated (undocumented)
+export const getContextualMenuItemClassNames: (theme: ITheme, disabled: boolean, expanded: boolean, checked: boolean, isAnchorLink: boolean, knownIcon: boolean, itemClassName?: string | undefined, dividerClassName?: string | undefined, iconClassName?: string | undefined, subMenuClassName?: string | undefined, primaryDisabled?: boolean | undefined, className?: string | undefined) => IContextualMenuItemStyles;
+
+// @public
+export const getContextualMenuItemStyles: (props: IContextualMenuItemStyleProps) => IContextualMenuItemStyles;
+
 // @public (undocumented)
 export function getContrastRatio(color1: IColor, color2: IColor): number;
 

packages/office-ui-fabric-react/src/components/ContextualMenu/index.ts

@@ -7,3 +7,8 @@ export * from './ContextualMenuItem';
 export * from './ContextualMenuItem.base';
 export * from './ContextualMenuItem.types';
 export { getMenuItemStyles } from './ContextualMenu.cnstyles';
+export {
+  // eslint-disable-next-line deprecation/deprecation
+  getItemClassNames as getContextualMenuItemClassNames,
+  getItemStyles as getContextualMenuItemStyles,
+} from './ContextualMenu.classNames';