[orca] Ensure a voice is generated for nesting level

[Joanmarie Diggs <joanied src gnome org>]

commit 813af0956664b613cc8adf2e58baec72a4dc8b23
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Wed Jun 12 15:40:30 2019 -0400

    Ensure a voice is generated for nesting level

 src/orca/speech_generator.py | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/src/orca/speech_generator.py b/src/orca/speech_generator.py
index 949124740..9167d510a 100644
--- a/src/orca/speech_generator.py
+++ b/src/orca/speech_generator.py
@@ -1275,6 +1275,13 @@ class SpeechGenerator(generator.Generator):
 
         return result
 
+    def _generateNestingLevel(self, obj, **args):
+        result = super()._generateNestingLevel(obj, **args)
+        if result:
+            result.extend(self.voice(SYSTEM))
+
+        return result
+
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