Bug 1286476 part 2 - Respect the playback rate when calculating phase boundaries; r=hiro

This implements the spec change in 21de090dac

The spec change refers to a binary 'animation direction' flag. Instead of that,
however, we just pass the playback rate along and use it inside
GetComputedTimingAt since this seems simpler.

Also, this patch moves the implementation of
KeyframeEffectReadOnly::GetComputedTiming from the header file into the .cpp
file. This is because with this change, GetComputedTiming needs to call
mAnimation->PlaybackRate() and so mozilla::dom::Animation needs to be a complete
type. However, simply including Animation.h doesn't work because of a cyclic
dependency between KeyframeEffect.h and Animation.h. We might be able to fix
this later but since yet-to-land bug 1049975 moves this code around a lot, I'd
rather not touch it too much just now.

MozReview-Commit-ID: 1h6XRh4xmfI

dom/animation/KeyframeEffect.cpp

@@ -221,9 +221,11 @@ void
 KeyframeEffectReadOnly::GetComputedTimingAsDict(
     ComputedTimingProperties& aRetVal) const
 {
+  double playbackRate = mAnimation ? mAnimation->PlaybackRate() : 1;
   const Nullable<TimeDuration> currentTime = GetLocalTime();
   GetComputedTimingDictionary(GetComputedTimingAt(currentTime,
-                                                  SpecifiedTiming()),
+                                                  SpecifiedTiming(),
+                                                  playbackRate),
                               currentTime,
                               SpecifiedTiming(),
                               aRetVal);
@@ -232,7 +234,8 @@ KeyframeEffectReadOnly::GetComputedTimingAsDict(
 ComputedTiming
 KeyframeEffectReadOnly::GetComputedTimingAt(
     const Nullable<TimeDuration>& aLocalTime,
-    const TimingParams& aTiming)
+    const TimingParams& aTiming,
+    double aPlaybackRate)
 {
   const StickyTimeDuration zeroDuration;
 
@@ -271,9 +274,15 @@ KeyframeEffectReadOnly::GetComputedTimingAt(
   // Calculate the time within the active interval.
   // https://w3c.github.io/web-animations/#active-time
   StickyTimeDuration activeTime;
-  if (localTime >=
-        std::min(StickyTimeDuration(aTiming.mDelay + result.mActiveDuration),
-                 result.mEndTime)) {
+
+  StickyTimeDuration beforeActiveBoundary =
+    std::min(StickyTimeDuration(aTiming.mDelay), result.mEndTime);
+  StickyTimeDuration activeAfterBoundary =
+    std::min(StickyTimeDuration(aTiming.mDelay + result.mActiveDuration),
+             result.mEndTime);
+
+  if (localTime > activeAfterBoundary ||
+      (aPlaybackRate >= 0 && localTime == activeAfterBoundary)) {
     result.mPhase = ComputedTiming::AnimationPhase::After;
     if (!result.FillsForwards()) {
       // The animation isn't active or filling at this time.
@@ -282,8 +291,8 @@ KeyframeEffectReadOnly::GetComputedTimingAt(
     activeTime = std::max(std::min(result.mActiveDuration,
                                    result.mActiveDuration + aTiming.mEndDelay),
                           zeroDuration);
-  } else if (localTime <
-               std::min(StickyTimeDuration(aTiming.mDelay), result.mEndTime)) {
+  } else if (localTime < beforeActiveBoundary ||
+             (aPlaybackRate < 0 && localTime == beforeActiveBoundary)) {
     result.mPhase = ComputedTiming::AnimationPhase::Before;
     if (!result.FillsBackwards()) {
       // The animation isn't active or filling at this time.
@@ -391,6 +400,15 @@ KeyframeEffectReadOnly::GetComputedTimingAt(
   return result;
 }
 
+ComputedTiming
+KeyframeEffectReadOnly::GetComputedTiming(const TimingParams* aTiming) const
+{
+  double playbackRate = mAnimation ? mAnimation->PlaybackRate() : 1;
+  return GetComputedTimingAt(GetLocalTime(),
+                             aTiming ? *aTiming : SpecifiedTiming(),
+                             playbackRate);
+}
+
 // https://w3c.github.io/web-animations/#in-play
 bool
 KeyframeEffectReadOnly::IsInPlay() const

dom/animation/KeyframeEffect.h

@@ -264,16 +264,13 @@ public:
   // (because it is not currently active and is not filling at this time).
   static ComputedTiming
   GetComputedTimingAt(const Nullable<TimeDuration>& aLocalTime,
-                      const TimingParams& aTiming);
+                      const TimingParams& aTiming,
+                      double aPlaybackRate);
 
   // Shortcut for that gets the computed timing using the current local time as
   // calculated from the timeline time.
   ComputedTiming
-  GetComputedTiming(const TimingParams* aTiming = nullptr) const
-  {
-    return GetComputedTimingAt(GetLocalTime(),
-                               aTiming ? *aTiming : SpecifiedTiming());
-  }
+  GetComputedTiming(const TimingParams* aTiming = nullptr) const;
 
   void
   GetComputedTimingAsDict(ComputedTimingProperties& aRetVal) const override;

gfx/layers/composite/AsyncCompositionManager.cpp

@@ -652,7 +652,8 @@ SampleAnimations(Layer* aLayer, TimeStamp aPoint)
 
           ComputedTiming computedTiming =
             dom::KeyframeEffectReadOnly::GetComputedTimingAt(
-              Nullable<TimeDuration>(elapsedDuration), timing);
+              Nullable<TimeDuration>(elapsedDuration), timing,
+              animation.playbackRate());
 
           MOZ_ASSERT(!computedTiming.mProgress.IsNull(),
                      "iteration progress should not be null");

layout/style/nsTransitionManager.cpp

@@ -91,7 +91,8 @@ ElementPropertyTransition::UpdateStartValueFromReplacedTransition()
                                          TimeStamp::Now(),
                                          mReplacedTransition->mStartTime,
                                          mReplacedTransition->mPlaybackRate),
-    mReplacedTransition->mTiming);
+    mReplacedTransition->mTiming,
+    mReplacedTransition->mPlaybackRate);
 
   if (!computedTiming.mProgress.IsNull()) {
     double valuePosition =

testing/web-platform/meta/web-animations/timing-model/animation-effects/phases-and-states.html.ini

@@ -1,5 +0,0 @@
-[phases-and-states.html]
-  type: testharness
-  [Phase calculation for a simple animation effect with negative playback rate]
-    expected: FAIL
-    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1286476