Bug 1173971 - Force core Xlib events on GTK3. r=karlt

testing/mochitest/runtests.py

@@ -1542,6 +1542,11 @@ class Mochitest(MochitestUtilsMixin):
         if not options.enableCPOWWarnings:
             browserEnv["DISABLE_UNSAFE_CPOW_WARNINGS"] = "1"
 
+        # Force use of core Xlib events on GTK3 to work around focus bug.
+        # See bug 1170342.
+        if mozinfo.info.get('toolkit') == 'gtk3':
+            browserEnv["GDK_CORE_DEVICE_EVENTS"] = "1"
+
         return browserEnv
 
     def cleanup(self, options):