Bug 1150064, part 1 - Implement the Animation.finish() method. r=birtles, r=smaug

dom/animation/Animation.cpp

@@ -217,6 +217,32 @@ Animation::GetFinished(ErrorResult& aRv)
   return mFinished;
 }
 
+void
+Animation::Finish(ErrorResult& aRv)
+{
+  // https://w3c.github.io/web-animations/#finish-an-animation
+
+  if (mPlaybackRate == 0 ||
+      (mPlaybackRate > 0 && EffectEnd() == TimeDuration::Forever())) {
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
+  }
+
+  TimeDuration limit =
+    mPlaybackRate > 0 ? TimeDuration(EffectEnd()) : TimeDuration(0);
+
+  SetCurrentTime(limit);
+
+  if (mPendingState == PendingState::PlayPending) {
+    CancelPendingTasks();
+    if (mReady) {
+      mReady->MaybeResolve(this);
+    }
+  }
+  UpdateFinishedState(true);
+  PostUpdate();
+}
+
 void
 Animation::Play(LimitBehavior aLimitBehavior)
 {

dom/animation/Animation.h

@@ -94,6 +94,7 @@ public:
   AnimationPlayState PlayState() const;
   virtual Promise* GetReady(ErrorResult& aRv);
   virtual Promise* GetFinished(ErrorResult& aRv);
+  virtual void Finish(ErrorResult& aRv);
   virtual void Play(LimitBehavior aLimitBehavior);
   virtual void Pause();
   bool IsRunningOnCompositor() const { return mIsRunningOnCompositor; }

dom/webidl/Animation.webidl

@@ -32,8 +32,9 @@ interface Animation {
   readonly attribute Promise<Animation> finished;
   /*
   void cancel ();
-  void finish ();
   */
+  [Throws]
+  void finish ();
   [BinaryName="playFromJS"]
   void play ();
   [BinaryName="pauseFromJS"]