Bug 1264540 - Turn on test_windowless_ime.html on e10s. r=jimm

Use plugin-utils.js's setTestPluginEnabledState to fix race.

MozReview-Commit-ID: 6eVTDJzdKR0

--HG--
extra : rebase_source : cd9d5d0a186b6b29c9d734cd941137ce15600244

dom/plugins/test/mochitest/mochitest.ini

@@ -138,5 +138,5 @@ skip-if = os != "win"
 [test_windowless_flash.html]
 skip-if = !(os == "win" && processor == "x86_64" && !e10s) # Bug 1253957
 [test_windowless_ime.html]
-skip-if = os != "win" || e10s
+skip-if = os != "win"
 [test_zero_opacity.html]

dom/plugins/test/mochitest/test_windowless_ime.html

@@ -36,7 +36,7 @@ function runTests() {
 }
 
 SimpleTest.waitForExplicitFinish();
-SpecialPowers.setTestPluginEnabledState(SpecialPowers.Ci.nsIPluginTag.STATE_ENABLED);
+setTestPluginEnabledState(SpecialPowers.Ci.nsIPluginTag.STATE_ENABLED);
   </script>
 </head>