[Extensions Menu] Remove child view from proper parent

We were trying to remove a child view from the wrong parent. Fix this.

This makes BrowserActionApiTest.Basic pass with the ExtensionsMenu
enabled.

Bug: 984654
Change-Id: I5e648e487fa173370f17eb841587f6136eb67e20
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2019926Reviewed-by: Peter Boström <pbos@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735027}

chrome/browser/ui/views/extensions/extensions_menu_view.cc

@@ -335,7 +335,7 @@ void ExtensionsMenuView::Update() {
     }
 
     for (ExtensionsMenuItemView* menu_item : views_to_move) {
-      section->container->RemoveChildView(menu_item);
+      section->menu_items->RemoveChildView(menu_item);
       InsertMenuItem(menu_item);
     }
   };