Bug 1170342 - Don't disable XInput2 for mochitests on GTK3, off by default now. r=karlt

testing/mochitest/runtests.py

@@ -1522,11 +1522,6 @@ 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):