[orca] Don't clear selection on descendants of tables

[Joanmarie Diggs <joanied src gnome org>]

commit 5f17e260e2dee7409790c0bcbb2f92700e54047a
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Mon Aug 26 15:47:26 2019 -0400

    Don't clear selection on descendants of tables
    
    We want to remove existing selections during caret navigation, but
    clearing the text selection on a full table is non-performant. So
    just clear it on the table itself and hope the user agent does the
    right thing. If it doesn't, let's ask them to.

 src/orca/scripts/web/script_utilities.py | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/src/orca/scripts/web/script_utilities.py b/src/orca/scripts/web/script_utilities.py
index 5d9828bd4..fa4e39271 100644
--- a/src/orca/scripts/web/script_utilities.py
+++ b/src/orca/scripts/web/script_utilities.py
@@ -4103,6 +4103,11 @@ class Utilities(script_utilities.Utilities):
         if self.isDocument(obj):
             return
 
+        # For performance reasons. If clearing the selection on a table doesn't
+        # clear it, file a bug against the user agent in question.
+        if self.getTable(obj):
+            return
+
         try:
             for child in obj:
                 self.clearTextSelection(child)