[MD History] Disable Clear Browsing Data button for supervised users.

chrome/browser/resources/md_history/side_bar.js

Index: chrome/browser/resources/md_history/side_bar.js
diff --git a/chrome/browser/resources/md_history/side_bar.js b/chrome/browser/resources/md_history/side_bar.js
index e0f7e13ad31582d00b8d81cf437613b61ce347b2..44c4ce11981f6449b7c93895078c25c96cb786c8 100644
--- a/chrome/browser/resources/md_history/side_bar.js
+++ b/chrome/browser/resources/md_history/side_bar.js
@@ -56,4 +56,12 @@ Polymer({
   onItemClick_: function(e) {
     e.preventDefault();
   },
+
+  /**
+   * If the user is a supervised user the delete button is not shown.
+   * @private
+   */
+  deletingAllowed_: function() {
+    return loadTimeData.getBoolean('allowDeletingHistory');
+  },
 });