Revert of Web Animations: Use a single animation clock

third_party/WebKit/Source/core/dom/Document.h

Index: third_party/WebKit/Source/core/dom/Document.h
diff --git a/third_party/WebKit/Source/core/dom/Document.h b/third_party/WebKit/Source/core/dom/Document.h
index cd7e295640facf68f6f224f07266ed784669cf1a..35df19358ce601449b2141f3529ad1b866c07bc0 100644
--- a/third_party/WebKit/Source/core/dom/Document.h
+++ b/third_party/WebKit/Source/core/dom/Document.h
@@ -959,7 +959,7 @@
     // Return a Locale for the default locale if the argument is null or empty.
     Locale& getCachedLocale(const AtomicString& locale = nullAtom);
 
-    AnimationClock& animationClock();
+    AnimationClock& animationClock() { return m_animationClock; }
     AnimationTimeline& timeline() const { return *m_timeline; }
     CompositorPendingAnimations& compositorPendingAnimations() { return m_compositorPendingAnimations; }
 
@@ -1357,6 +1357,7 @@
     using LocaleIdentifierToLocaleMap = HashMap<AtomicString, OwnPtr<Locale>>;
     LocaleIdentifierToLocaleMap m_localeCache;
 
+    AnimationClock m_animationClock;
     PersistentWillBeMember<AnimationTimeline> m_timeline;
     CompositorPendingAnimations m_compositorPendingAnimations;