Bug 1311196 - Part 1: Add isOMTAEnabled() in testcommon.js. r=boris

MozReview-Commit-ID: FtJTXlsTACn

--HG--
extra : rebase_source : fe2a1df9c8edf3315d77b1f4070852234f2df070

dom/animation/test/chrome/test_restyles.html

@@ -64,9 +64,7 @@ function ensureElementRemoval(aElement) {
 
 SimpleTest.waitForExplicitFinish();
 
-const OMTAPrefKey = 'layers.offmainthreadcomposition.async-animations';
-var omtaEnabled = SpecialPowers.DOMWindowUtils.layerManagerRemote &&
-                  SpecialPowers.getBoolPref(OMTAPrefKey);
+var omtaEnabled = isOMTAEnabled();
 
 var isAndroid = !!navigator.userAgent.includes("Android");
 

dom/animation/test/chrome/test_running_on_compositor.html

@@ -50,9 +50,7 @@ div {
 /** Test for bug 1045994 - Add a chrome-only property to inspect if an
     animation is running on the compositor or not **/
 
-const OMTAPrefKey = 'layers.offmainthreadcomposition.async-animations';
-var omtaEnabled = SpecialPowers.DOMWindowUtils.layerManagerRemote &&
-                  SpecialPowers.getBoolPref(OMTAPrefKey);
+var omtaEnabled = isOMTAEnabled();
 
 function assert_animation_is_running_on_compositor(animation, desc) {
   assert_equals(animation.isRunningOnCompositor, omtaEnabled,

dom/animation/test/mozilla/file_deferred_start.html

@@ -81,10 +81,7 @@ async_test(function(t) {
 // us through a different code path.
 async_test(function(t) {
   // This test only applies to compositor animations
-  const OMTAPrefKey = 'layers.offmainthreadcomposition.async-animations';
-  var omtaEnabled = SpecialPowers.DOMWindowUtils.layerManagerRemote &&
-                    opener.SpecialPowers.getBoolPref(OMTAPrefKey);
-  if (!omtaEnabled) {
+  if (!isOMTAEnabled()) {
     t.done();
     return;
   }

dom/animation/test/testcommon.js

@@ -206,3 +206,11 @@ function setupSynchronousObserver(t, target, subtree) {
   return observer;
 }
 
+/**
+ * Returns true if off-main-thread animations.
+ */
+function isOMTAEnabled() {
+  const OMTAPrefKey = 'layers.offmainthreadcomposition.async-animations';
+  return SpecialPowers.DOMWindowUtils.layerManagerRemote &&
+         SpecialPowers.getBoolPref(OMTAPrefKey);
+}