Simplify time tracking in SMILTimeContainer

third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h

 /*
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 39 matching lines @@
 
     void schedule(SVGSMILElement*, SVGElement*, const QualifiedName&);
     void unschedule(SVGSMILElement*, SVGElement*, const QualifiedName&);
     void notifyIntervalsChanged();
 
     SMILTime elapsed() const;
 
     bool isPaused() const;
     bool isStarted() const;
 
-    void begin();
+    void start();
     void pause();
     void resume();
     void setElapsed(SMILTime);
 
     void serviceAnimations();
     bool hasAnimations() const;
 
     void setDocumentOrderIndexesDirty() { m_documentOrderIndexesDirty = true; }
 
     // Advance the animation timeline a single frame.
@@ skipping 18 matching lines @@
     enum AnimationPolicyOnceAction {
         // Restart OnceTimer if the timeline is not paused.
         RestartOnceTimerIfNotPaused,
         // Restart OnceTimer.
         RestartOnceTimer,
         // Cancel OnceTimer.
         CancelOnceTimer
     };
 
     bool isTimelineRunning() const;
-    void scheduleAnimationFrame(SMILTime fireTime);
+    void synchronizeToDocumentTimeline();
+    void scheduleAnimationFrame(double delayTime);
     void cancelAnimationFrame();
     void wakeupTimerFired(TimerBase*);
     void scheduleAnimationPolicyTimer();
     void cancelAnimationPolicyTimer();
     void animationPolicyTimerFired(TimerBase*);
     ImageAnimationPolicy animationPolicy() const;
     bool handleAnimationPolicy(AnimationPolicyOnceAction);
     void updateAnimationsAndScheduleFrameIfNeeded(SMILTime elapsed, bool seekToTime = false);
     SMILTime updateAnimations(SMILTime elapsed, bool seekToTime = false);
     void serviceOnNextFrame();
     void scheduleWakeUp(double delayTime, FrameSchedulingState);
     bool hasPendingSynchronization() const;
 
     void updateDocumentOrderIndexes();
-    double lastResumeTime() const { return m_resumeTime ? m_resumeTime : m_beginTime; }
 
     SVGSVGElement& ownerSVGElement() const;
     Document& document() const;
-    double currentTime() const;
 
-    double m_beginTime;
-    double m_pauseTime;
-    double m_resumeTime;
-    double m_accumulatedActiveTime;
-    double m_presetStartTime;
+    // The latest "restart" time for the time container's timeline. If the
+    // timeline has not been manipulated (seeked, paused) this will be zero.
+    double m_presentationTime;
+    // The time on the document timeline corresponding to |m_presentationTime|.
+    double m_referenceTime;
 
     FrameSchedulingState m_frameSchedulingState;
+    bool m_started; // The timeline has been started.
+    bool m_paused; // The timeline is paused.
+
     bool m_documentOrderIndexesDirty;
 
     Timer<SMILTimeContainer> m_wakeupTimer;
     Timer<SMILTimeContainer> m_animationPolicyOnceTimer;
 
     using ElementAttributePair = std::pair<WeakMember<SVGElement>, QualifiedName>;
     using AnimationsLinkedHashSet = HeapLinkedHashSet<WeakMember<SVGSMILElement>>;
     using GroupedAnimationsMap = HeapHashMap<ElementAttributePair, Member<AnimationsLinkedHashSet>>;
     GroupedAnimationsMap m_scheduledAnimations;
 
     Member<SVGSVGElement> m_ownerSVGElement;
 
 #if ENABLE(ASSERT)
     bool m_preventScheduledAnimationsChanges;
 #endif
 };
 } // namespace blink
 
 #endif // SMILTimeContainer_h