Revert of Remove unnecessary member SampledEffect::m_priority and use…

… Animation::priority() instead. (patchset #1 id:1 of https://codereview.chromium.org/799533002/)

Reason for revert:
This CL breaks AnimationAnimationStackTest.ForwardsFillDiscarding unit test in Oilpan build.

Original issue's description:
> Remove unnecessary member SampledEffect::m_priority and use Animation::priority() instead.
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=187000

TBR=dstockwell@chromium.org,timloh@chromium.org,sigbjornf@opera.com
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/805753002

git-svn-id: svn://svn.chromium.org/blink/trunk@187130 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Source/core/animation/AnimationStack.cpp

@@ -101,7 +101,7 @@ WillBeHeapHashMap<CSSPropertyID, RefPtrWillBeMember<Interpolation> > AnimationSt
         nonCopyingSort(effects.begin(), effects.end(), compareEffects);
         animationStack->simplifyEffects();
         for (const auto& effect : effects) {
-            if (effect->animation()->priority() != priority || (cancelledAnimationPlayers && cancelledAnimationPlayers->contains(effect->animation()->player())))
+            if (effect->priority() != priority || (cancelledAnimationPlayers && effect->animation() && cancelledAnimationPlayers->contains(effect->animation()->player())))
                 continue;
             copyToActiveInterpolationMap(effect->interpolations(), result);
         }

Source/core/animation/SampledEffect.cpp

@@ -16,6 +16,7 @@ SampledEffect::SampledEffect(Animation* animation, PassOwnPtrWillBeRawPtr<WillBe
 #endif
     , m_interpolations(interpolations)
     , m_sequenceNumber(animation->player()->sequenceNumber())
+    , m_priority(animation->priority())
 {
     ASSERT(m_interpolations && !m_interpolations->isEmpty());
 }

Source/core/animation/SampledEffect.h

@@ -34,6 +34,7 @@ class SampledEffect : public NoBaseWillBeGarbageCollected<SampledEffect> {
 
     Animation* animation() const { return m_animation; }
     unsigned sequenceNumber() const { return m_sequenceNumber; }
+    Animation::Priority priority() const { return m_priority; }
 
     void removeReplacedInterpolationsIfNeeded(const BitArray<numCSSProperties>&);
 
@@ -48,6 +49,7 @@ class SampledEffect : public NoBaseWillBeGarbageCollected<SampledEffect> {
 #endif
     OwnPtrWillBeMember<WillBeHeapVector<RefPtrWillBeMember<Interpolation>>> m_interpolations;
     const unsigned m_sequenceNumber;
+    Animation::Priority m_priority;
 };
 
 } // namespace blink