10 files changed, 27 insertions, 12 deletions
diff --git a/dom/animation/test/crashtests/crashtests.list b/dom/animation/test/crashtests/crashtests.list
index f61d7f876..29b18769a 100644
--- a/dom/animation/test/crashtests/crashtests.list
+++ b/dom/animation/test/crashtests/crashtests.list
@@ -1,13 +1,13 @@
 pref(dom.animations-api.core.enabled,true) load 1239889-1.html
 pref(dom.animations-api.core.enabled,true) load 1244595-1.html
-pref(dom.animations-api.core.enabled,true) load 1216842-1.html
-pref(dom.animations-api.core.enabled,true) load 1216842-2.html
-pref(dom.animations-api.core.enabled,true) load 1216842-3.html
-pref(dom.animations-api.core.enabled,true) load 1216842-4.html
-pref(dom.animations-api.core.enabled,true) load 1216842-5.html
-pref(dom.animations-api.core.enabled,true) load 1216842-6.html
+pref(dom.animations-api.core.enabled,true) pref(dom.animations-api.timelines.enabled,true) load 1216842-1.html
+pref(dom.animations-api.core.enabled,true) pref(dom.animations-api.timelines.enabled,true) load 1216842-2.html
+pref(dom.animations-api.core.enabled,true) pref(dom.animations-api.timelines.enabled,true) load 1216842-3.html
+pref(dom.animations-api.core.enabled,true) pref(dom.animations-api.timelines.enabled,true) load 1216842-4.html
+pref(dom.animations-api.core.enabled,true) pref(dom.animations-api.timelines.enabled,true) load 1216842-5.html
+pref(dom.animations-api.core.enabled,true) pref(dom.animations-api.timelines.enabled,true) load 1216842-6.html
 pref(dom.animations-api.core.enabled,true) load 1272475-1.html
 pref(dom.animations-api.core.enabled,true) load 1272475-2.html
 pref(dom.animations-api.core.enabled,true) load 1278485-1.html
-pref(dom.animations-api.core.enabled,true) load 1277272-1.html
+pref(dom.animations-api.core.enabled,true) pref(dom.animations-api.timelines.enabled,true) load 1277272-1.html
 pref(dom.animations-api.core.enabled,true) load 1290535-1.html
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index 0fed2db01..4d6579a89 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -2923,6 +2923,15 @@ nsDocument::IsWebAnimationsEnabled(JSContext* /*unused*/, JSObject* /*unused*/)
          Preferences::GetBool("dom.animations-api.core.enabled");
 }
 
+bool
+nsDocument::AreWebAnimationsTimelinesEnabled(JSContext* /*unused*/, JSObject* /*unused*/)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  return nsContentUtils::IsCallerChrome() ||
+         Preferences::GetBool("dom.animations-api.timelines.enabled");
+}
+
 DocumentTimeline*
 nsDocument::Timeline()
 {
diff --git a/dom/base/nsDocument.h b/dom/base/nsDocument.h
index 951ed2616..a1fb04c6b 100644
--- a/dom/base/nsDocument.h
+++ b/dom/base/nsDocument.h
@@ -433,6 +433,8 @@ public:
 
   static bool IsElementAnimateEnabled(JSContext* aCx, JSObject* aObject);
   static bool IsWebAnimationsEnabled(JSContext* aCx, JSObject* aObject);
+  static bool AreWebAnimationsTimelinesEnabled(JSContext* aCx, JSObject* aObject);
+
   virtual mozilla::dom::DocumentTimeline* Timeline() override;
   virtual void GetAnimations(
       nsTArray<RefPtr<mozilla::dom::Animation>>& aAnimations) override;
diff --git a/dom/webidl/Animation.webidl b/dom/webidl/Animation.webidl
index 615084f75..9fdea5ade 100644
--- a/dom/webidl/Animation.webidl
+++ b/dom/webidl/Animation.webidl
@@ -19,7 +19,7 @@ interface Animation : EventTarget {
   attribute DOMString id;
   [Func="nsDocument::IsWebAnimationsEnabled", Pure]
   attribute AnimationEffectReadOnly? effect;
-  [Func="nsDocument::IsWebAnimationsEnabled"]
+  [Func="nsDocument::AreWebAnimationsTimelinesEnabled"]
   attribute AnimationTimeline? timeline;
   [BinaryName="startTimeAsDouble"]
   attribute double? startTime;
diff --git a/dom/webidl/AnimationTimeline.webidl b/dom/webidl/AnimationTimeline.webidl
index fe3d0fb49..4cf5567ce 100644
--- a/dom/webidl/AnimationTimeline.webidl
+++ b/dom/webidl/AnimationTimeline.webidl
@@ -10,7 +10,7 @@
  * liability, trademark and document use rules apply.
  */
 
-[Func="nsDocument::IsWebAnimationsEnabled"]
+[Func="nsDocument::AreWebAnimationsTimelinesEnabled"]
 interface AnimationTimeline {
   [BinaryName="currentTimeAsDouble"]
   readonly attribute double? currentTime;
diff --git a/dom/webidl/Document.webidl b/dom/webidl/Document.webidl
index 26985202b..46db00876 100644
--- a/dom/webidl/Document.webidl
+++ b/dom/webidl/Document.webidl
@@ -312,7 +312,7 @@ partial interface Document {
 
 // http://w3c.github.io/web-animations/#extensions-to-the-document-interface
 partial interface Document {
-  [Func="nsDocument::IsWebAnimationsEnabled"]
+  [Func="nsDocument::AreWebAnimationsTimelinesEnabled"]
   readonly attribute DocumentTimeline timeline;
   [Func="nsDocument::IsWebAnimationsEnabled"]
   sequence<Animation> getAnimations();
diff --git a/dom/webidl/DocumentTimeline.webidl b/dom/webidl/DocumentTimeline.webidl
index 916b1a491..f10e2b365 100644
--- a/dom/webidl/DocumentTimeline.webidl
+++ b/dom/webidl/DocumentTimeline.webidl
@@ -14,7 +14,7 @@ dictionary DocumentTimelineOptions {
   DOMHighResTimeStamp originTime = 0;
 };
 
-[Func="nsDocument::IsWebAnimationsEnabled",
+[Func="nsDocument::AreWebAnimationsTimelinesEnabled",
  Constructor (optional DocumentTimelineOptions options)]
 interface DocumentTimeline : AnimationTimeline {
 };
diff --git a/dom/xslt/tests/mochitest/test_bug1135764.html b/dom/xslt/tests/mochitest/test_bug1135764.html
index 5a7410e37..b1f627c87 100644
--- a/dom/xslt/tests/mochitest/test_bug1135764.html
+++ b/dom/xslt/tests/mochitest/test_bug1135764.html
@@ -27,7 +27,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1135764
   }
   addLoadEvent(function() {
     SpecialPowers.pushPrefEnv(
-      { "set": [[ "dom.animations-api.core.enabled", true]] },
+      { "set": [[ "dom.animations-api.timelines.enabled", true]] },
       function() {
         var ifr = document.querySelector("iframe");
         ifr.onload = function() {
diff --git a/layout/style/test/mochitest.ini b/layout/style/test/mochitest.ini
index 01aafefd9..8b36e3e1e 100644
--- a/layout/style/test/mochitest.ini
+++ b/layout/style/test/mochitest.ini
@@ -1,4 +1,7 @@
 [DEFAULT]
+prefs =
+  dom.animations-api.core.enabled=true
+  dom.animations-api.timelines.enabled=true
 support-files =
   animation_utils.js
   ccd-quirks.html
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 9f2c48b0b..a81f3ba55 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2718,6 +2718,7 @@ pref("dom.animations-api.core.enabled", false);
 #else
 pref("dom.animations-api.core.enabled", true);
 #endif
+pref("dom.animations-api.timelines.enabled", false);
 
 // Is support for the Element.animate() function (a subset of the Web Animations
 // API) enabled?