[orca] Don't descend elements for on-screen children if _treatObjectAsWhole() is true

[Joanmarie Diggs <joanied src gnome org>]

commit 90d9576fd15f485531970be4242a84460c2ac0a0
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Sat May 9 16:44:42 2020 -0400

    Don't descend elements for on-screen children if _treatObjectAsWhole() is true
    
    This should help improve performance of getting status bar items for
    web apps / Electron apps (e.g. VSCode).

 src/orca/scripts/web/script_utilities.py | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/src/orca/scripts/web/script_utilities.py b/src/orca/scripts/web/script_utilities.py
index a4d047798..c8fefaf21 100644
--- a/src/orca/scripts/web/script_utilities.py
+++ b/src/orca/scripts/web/script_utilities.py
@@ -4964,6 +4964,12 @@ class Utilities(script_utilities.Utilities):
         self._lastQueuedLiveRegionEvent = event
         return True
 
+    def getOnScreenObjects(self, root, extents=None):
+        if self._treatObjectAsWhole(root):
+            return [root]
+
+        return super().getOnScreenObjects(root, extents)
+
     def getPageObjectCount(self, obj):
         result = {'landmarks': 0,
                   'headings': 0,