[orca] Restore clearing cache for Gecko windows because some events are missing

[Joanmarie Diggs <joanied src gnome org>]

commit 109c4dbeb9d1178621bc435c97dbe4febb6ef78b
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Wed Nov 21 07:17:38 2018 -0500

    Restore clearing cache for Gecko windows because some events are missing

 src/orca/scripts/toolkits/Gecko/script_utilities.py | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/src/orca/scripts/toolkits/Gecko/script_utilities.py 
b/src/orca/scripts/toolkits/Gecko/script_utilities.py
index 4c627de6e..3fd9190e1 100644
--- a/src/orca/scripts/toolkits/Gecko/script_utilities.py
+++ b/src/orca/scripts/toolkits/Gecko/script_utilities.py
@@ -182,3 +182,8 @@ class Utilities(web.Utilities):
             return True
 
         return False
+
+    def canBeActiveWindow(self, window, clearCache=False):
+        # We apparently having missing events from Gecko requiring
+        # we update the cache. This is not performant. :(
+        return super().canBeActiveWindow(window, True)