Fix "Managed by..." menu item enable state

managed by menu item should be setVibility(View.VISIBLE) and
setEnabled(false) when shows up.

App menu should be kept open after disabled item has been clicked.
Previously click on the item will close the app menu.
This CL also fixes TalkBack announcing "disabled" for the item.

Bug: 997053
Change-Id: I4442bd889c30b850c7287869054a3beff2455b9c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2351419Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Gang Wu <gangwu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797409}

chrome/android/java/src/org/chromium/chrome/browser/app/appmenu/AppMenuPropertiesDelegateImpl.java

@@ -295,7 +295,11 @@ public class AppMenuPropertiesDelegateImpl implements AppMenuPropertiesDelegate
         // Only display the Enter VR button if VR Shell Dev environment is enabled.
         menu.findItem(R.id.enter_vr_id).setVisible(shouldShowEnterVr());
 
-        menu.findItem(R.id.managed_by_menu_id).setVisible(shouldShowManagedByMenuItem(currentTab));
+        MenuItem managedByMenuItem = menu.findItem(R.id.managed_by_menu_id);
+        managedByMenuItem.setVisible(shouldShowManagedByMenuItem(currentTab));
+        // TODO(https://crbug.com/1092175): Enable "managed by" menu item after chrome://management
+        // page is added.
+        managedByMenuItem.setEnabled(false);
     }
 
     private void prepareCommonMenuItems(Menu menu, @MenuGroup int menuGroup, boolean isIncognito) {

chrome/android/java/src/org/chromium/chrome/browser/app/appmenu/ManagedByMenuItemViewBinder.java

@@ -37,8 +37,6 @@ class ManagedByMenuItemViewBinder implements CustomViewBinder {
         if (convertView == null) {
             convertView = inflater.inflate(R.layout.managed_by_menu_item, parent, false);
         }
-
-        convertView.setEnabled(false);
         convertView.setFocusable(false);
 
         return convertView;