Bug 1859171 - Use AnimationFrameProvider mixin with DedicatedWorkerGlobalScope. r=webidl,emilio

This patch removes the duplicate definitions of requestAnimationFrame
and cancelAnimationFrame in DedicatedWorkerGlobalScope in favour of
using the AnimationFrameProvider mixin. We couldn't before when there
was a worker only pref limitation, but that was removed in another
patch.

This patch has no functional change.

Differential Revision: https://phabricator.services.mozilla.com/D191026

dom/webidl/DedicatedWorkerGlobalScope.webidl

@@ -27,15 +27,6 @@ interface DedicatedWorkerGlobalScope : WorkerGlobalScope {
 
   attribute EventHandler onmessage;
   attribute EventHandler onmessageerror;
-
-  // https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#animation-frames
-  // Ideally we would just include AnimationFrameProvider to add the interface,
-  // but we cannot make an include conditional.
-  [Throws]
-  long requestAnimationFrame(FrameRequestCallback callback);
-
-  [Throws]
-  undefined cancelAnimationFrame(long handle);
 };
 
 // https://w3c.github.io/webrtc-encoded-transform/#RTCEncodedAudioFrame-methods
@@ -43,3 +34,6 @@ partial interface DedicatedWorkerGlobalScope {
   [Pref="media.peerconnection.enabled",
    Pref="media.peerconnection.scripttransform.enabled"] attribute EventHandler onrtctransform;
 };
+
+// https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#animation-frames
+DedicatedWorkerGlobalScope includes AnimationFrameProvider;