Revert "[Switch Access] Detect menus and modal dialogs"

This reverts commit 2e0cfc50.

Reason for revert: crbug/1103769

Original change's description:
> [Switch Access] Detect menus and modal dialogs
> 
> If the user navigates to a modal or system menu (other than by focus
> automatically jumping there), we should still use the custom behavior
> for modals.
> 
> AX-Relnotes: n/a.
> Bug: None.
> Change-Id: Ie0b963f1540568cdd8f249ee016e787de45c0b3b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2270468
> Auto-Submit: Anastasia Helfinstein <anastasi@google.com>
> Reviewed-by: David Tseng <dtseng@chromium.org>
> Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
> Cr-Commit-Position: refs/heads/master@{#785946}

TBR=dtseng@chromium.org,anastasi@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: None.
Change-Id: I4d285382d993d5082814da6f43e0122558777010
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2290350Reviewed-by: Anastasia Helfinstein <anastasi@google.com>
Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
Cr-Commit-Position: refs/heads/master@{#786906}

chrome/browser/resources/chromeos/accessibility/switch_access/nodes/node_wrapper.js

@@ -351,11 +351,6 @@ class RootNodeWrapper extends SARootNode {
          rootNode.parent.role === chrome.automation.RoleType.WINDOW)) {
       return WindowRootNode.buildTree(rootNode);
     }
-    if (rootNode.role === chrome.automation.RoleType.MENU ||
-        rootNode.role === chrome.automation.RoleType.MENU_BAR ||
-        rootNode.modal) {
-      return ModalDialogRootNode.buildTree(rootNode);
-    }
 
     const root = new RootNodeWrapper(rootNode);
     const childConstructor = (node) => NodeWrapper.create(node, root);