Bug 1379564 - Use BaseTimeDuration::bool() to check the TimeDuration is not zero. r=birtles

In TimingParams::CalcActiveDuration(), we intentionally use IsZero() instead
of the bool() operator since the value |aDuration| is Maybe<StickyTimeDuration>
, it's easily misread as Maybe::bool().

MozReview-Commit-ID: D5Nb7cxh7wi

--HG--
extra : rebase_source : e30fe73c5b02d09ab5116bcfc6ca20a902b13b75

dom/animation/AnimationEffectReadOnly.cpp

@@ -161,7 +161,7 @@ AnimationEffectReadOnly::GetComputedTimingAt(
       = std::max(StickyTimeDuration(localTime - aTiming.Delay()),
                  zeroDuration);
   } else {
-    MOZ_ASSERT(result.mActiveDuration != zeroDuration,
+    MOZ_ASSERT(result.mActiveDuration,
                "How can we be in the middle of a zero-duration interval?");
     result.mPhase = ComputedTiming::AnimationPhase::Active;
     result.mActiveTime = localTime - aTiming.Delay();
@@ -170,7 +170,7 @@ AnimationEffectReadOnly::GetComputedTimingAt(
   // Convert active time to a multiple of iterations.
   // https://w3c.github.io/web-animations/#overall-progress
   double overallProgress;
-  if (result.mDuration == zeroDuration) {
+  if (!result.mDuration) {
     overallProgress = result.mPhase == ComputedTiming::AnimationPhase::Before
                       ? 0.0
                       : result.mIterations;

dom/animation/AnimationEffectReadOnly.h

@@ -53,7 +53,7 @@ public:
   bool IsInEffect() const;
   bool IsActiveDurationZero() const
   {
-    return SpecifiedTiming().ActiveDuration() == StickyTimeDuration();
+    return !SpecifiedTiming().ActiveDuration();
   }
 
   already_AddRefed<AnimationEffectTimingReadOnly> Timing();

dom/animation/TimingParams.h

@@ -133,7 +133,7 @@ struct TimingParams
     // Web Animations says that the active duration is zero. This is to
     // ensure that the result is defined when the other argument is Infinity.
     static const StickyTimeDuration zeroDuration;
-    if (!aDuration || *aDuration == zeroDuration || aIterations == 0.0) {
+    if (!aDuration || aDuration->IsZero() || aIterations == 0.0) {
       return zeroDuration;
     }