Move CSS animations use counters to UseCounter

third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp

Index: third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
diff --git a/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp b/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
index 39a15c6b8a3760c1ee1ebc041080462e0fe64027..289a723903c41a5273de44233a1e6b9633abb099 100644
--- a/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
+++ b/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
@@ -131,6 +131,9 @@ static StringKeyframeEffectModel* createKeyframeEffectModel(
                       ("WebCore.Animation.CSSProperties"));
   for (CSSPropertyID property : specifiedPropertiesForUseCounter) {
     DCHECK(isValidCSSPropertyID(property));
+    UseCounter::countAnimatedCSS(elementForScoping->document(), property);
+
+    // TODO(crbug.com/458925): Remove legacy histogram and counts
     propertyHistogram.sample(
         UseCounter::mapCSSPropertyIdToCSSSampleIdForHistogram(property));
   }
@@ -591,7 +594,9 @@ void CSSAnimations::maybeApplyPendingUpdate(Element* element) {
     runningTransition.animation = animation;
     m_transitions.set(id, runningTransition);
     DCHECK(isValidCSSPropertyID(id));
+    UseCounter::countAnimatedCSS(element->document(), id);
 
+    // TODO(crbug.com/458925): Remove legacy histogram and counts
     DEFINE_STATIC_LOCAL(SparseHistogram, propertyHistogram,
                         ("WebCore.Animation.CSSProperties"));
     propertyHistogram.sample(