Adding deprecation message

ui/components/ui/icon-border/icon-border.js

@@ -2,6 +2,14 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import classnames from 'classnames';
 
+/**
+ * @deprecated The `<IconBorder />` component has been deprecated in favor of the `<AvatarBase />` component from the component-library.
+ * Please update your code to use the new `<AvatarBase>` component instead, which can be found at ./ui/components/component-library/avatar-base/avatar-base.js.
+ * You can find documentation for the new AvatarBase component in the MetaMask Storybook:
+ * {@link https://metamask.github.io/metamask-storybook/?path=/docs/components-componentlibrary-avatarbase--docs}
+ * If you would like to help with the replacement of the old IconBorder component, please submit a pull request
+ */
+
 export default function IconBorder({ children, size, className }) {
   const borderStyle = { height: `${size}px`, width: `${size}px` };
   return (

ui/components/ui/icon-border/icon-border.stories.js

@@ -1,9 +1,11 @@
 import React from 'react';
+import { Severity } from '../../../helpers/constants/design-system';
+import { BannerAlert } from '../../component-library';
+
 import IconBorder from './icon-border';
 
 export default {
   title: 'Components/UI/IconBorder',
-
   component: IconBorder,
   argTypes: {
     className: {
@@ -19,10 +21,20 @@ export default {
   args: {
     className: '',
     children: 'D',
-    size: 5,
+    size: 32,
   },
 };
 
-export const DefaultStory = (args) => <IconBorder {...args} />;
+export const DefaultStory = (args) => (
+  <>
+    <BannerAlert
+      severity={Severity.Warning}
+      title="Deprecated"
+      description="<IconBorder/> has been deprecated in favour of the <AvatarBase /> component"
+      marginBottom={4}
+    />
+    <IconBorder {...args} />
+  </>
+);
 
 DefaultStory.storyName = 'Default';