[orca] Chromium: Don't cache the parent due to missing events in omnibox

[Joanmarie Diggs <joanied src gnome org>]

commit 12a38f34888f9489cb5114e349d71538b83501c1
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Wed Aug 21 10:09:54 2019 -0400

    Chromium: Don't cache the parent due to missing events in omnibox

 src/orca/scripts/toolkits/Chromium/script.py | 8 ++++++++
 1 file changed, 8 insertions(+)
---
diff --git a/src/orca/scripts/toolkits/Chromium/script.py b/src/orca/scripts/toolkits/Chromium/script.py
index c91ffb291..a6d444703 100644
--- a/src/orca/scripts/toolkits/Chromium/script.py
+++ b/src/orca/scripts/toolkits/Chromium/script.py
@@ -51,6 +51,14 @@ class Script(web.Script):
 
         self.presentIfInactive = False
 
+        # Chromium fails to emit notifications when objects are reparented,
+        # leading to dead accessibles in the ancestry.
+        app.setCacheMask(pyatspi.cache.DEFAULT ^
+                         pyatspi.cache.CHILDREN ^
+                         pyatspi.cache.NAME ^
+                         pyatspi.cache.DESCRIPTION ^
+                         pyatspi.cache.PARENT)
+
     def getBrailleGenerator(self):
         """Returns the braille generator for this script."""