[orca] Don't treat MathML as "layout only" (as defined by Orca's default code)

[Joanmarie Diggs <joanied src gnome org>]

commit d822d2f3789d50f489275ea58e26e8cd91ac2fac
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Thu Jul 2 02:46:22 2015 -0400

    Don't treat MathML as "layout only" (as defined by Orca's default code)

 src/orca/scripts/web/script_utilities.py |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)
---
diff --git a/src/orca/scripts/web/script_utilities.py b/src/orca/scripts/web/script_utilities.py
index 348f59f..35bd892 100644
--- a/src/orca/scripts/web/script_utilities.py
+++ b/src/orca/scripts/web/script_utilities.py
@@ -1721,6 +1721,22 @@ class Utilities(script_utilities.Utilities):
         self._isGridDescendant[hash(obj)] = rv
         return rv
 
+    def isLayoutOnly(self, obj):
+        if not obj:
+            return False
+
+        rv = self._isLayoutOnly.get(hash(obj))
+        if rv is not None:
+            return rv
+
+        if self.isMath(obj):
+            rv = False
+        else:
+            rv = super().isLayoutOnly(obj)
+
+        self._isLayoutOnly[hash(obj)] = rv
+        return rv
+
     def isOffScreenLabel(self, obj):
         if not (obj and self.inDocumentContent(obj)):
             return False