Prune use of Animation::PlayStateInternal.

PlayStateInternal returns a value for the play state of an animation
that is not to spec. It includes a pending state that is not a valid
value for the play state. This CL is part of a series of patches to
bring the implementation of web animations in line with the spec.

Bug: 958433
Change-Id: Ifd189641e83972e63d474cd99db391aad3dff406
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1715764
Commit-Queue: Kevin Ellis <kevers@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Reviewed-by: Majid Valipour <majidvp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#681385}

third_party/blink/renderer/core/animation/animation.cc

@@ -708,13 +708,18 @@ Animation::AnimationPlayState Animation::CalculatePlayState() const {
     return kPaused;
   if (internal_play_state_ == kIdle)
     return kIdle;
-  if (current_time_pending_ || (!start_time_ && playback_rate_ != 0))
+  if (NeedsCompositorTimeSync())
     return kPending;
   if (Limited())
     return kFinished;
   return kRunning;
 }
 
+Animation::AnimationPlayState Animation::GetPlayState() const {
+  DCHECK_NE(animation_play_state_, kUnset);
+  return animation_play_state_;
+}
+
 // https://drafts.csswg.org/web-animations/#play-states
 Animation::AnimationPlayState Animation::CalculateAnimationPlayState() const {
   // 1. All of the following conditions are true:

third_party/blink/renderer/core/animation/animation.h

@@ -130,7 +130,7 @@ class CORE_EXPORT Animation final : public EventTargetWithInlineData,
   bool Paused() const { return paused_ && !is_paused_for_testing_; }
   static const char* PlayStateString(AnimationPlayState);
   String playState() const { return PlayStateString(animation_play_state_); }
-  AnimationPlayState PlayStateInternal() const;
+
   bool pending() const;
 
   void pause(ExceptionState& = ASSERT_NO_EXCEPTION);
@@ -147,6 +147,21 @@ class CORE_EXPORT Animation final : public EventTargetWithInlineData,
     return !(PlayStateInternal() == kIdle || Limited() || paused_ ||
              is_paused_for_testing_);
   }
+
+  // TODO(crbug/960944): Deprecate. This version of the play state is not to
+  // spec due to the inclusion of a 'pending' state. Whether or not an animation
+  // is pending is separate from the actual play state.
+  AnimationPlayState PlayStateInternal() const;
+
+  // Indicates if the animation is out of sync with the compositor. A change to
+  // the play state (running/paused) requires synchronization with the
+  // compositor.
+  bool NeedsCompositorTimeSync() const {
+    return current_time_pending_ || (!start_time_ && playback_rate_ != 0);
+  }
+
+  AnimationPlayState GetPlayState() const;
+
   bool Limited() const { return Limited(CurrentTimeInternal()); }
   bool FinishedInternal() const { return finished_; }
 

third_party/blink/renderer/core/animation/compositor_animations.cc

@@ -73,10 +73,12 @@ bool ConsiderAnimationAsIncompatible(const Animation& animation,
   if (&animation == &animation_to_add)
     return false;
 
-  switch (animation.PlayStateInternal()) {
+  if (animation.NeedsCompositorTimeSync())
+    return true;
+
+  switch (animation.GetPlayState()) {
     case Animation::kIdle:
       return false;
-    case Animation::kPending:
     case Animation::kRunning:
       return true;
     case Animation::kPaused:

third_party/blink/renderer/core/animation/pending_animations.cc

@@ -142,8 +142,7 @@ void PendingAnimations::NotifyCompositorAnimationStarted(
   animations.swap(waiting_for_compositor_animation_start_);
 
   for (auto animation : animations) {
-    if (animation->startTime() ||
-        animation->PlayStateInternal() != Animation::kPending ||
+    if (animation->startTime() || !animation->NeedsCompositorTimeSync() ||
         !animation->timeline() || !animation->timeline()->IsActive()) {
       // Already started or no longer relevant.
       continue;