Simplify time tracking in SMILTimeContainer

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

Index: third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h
diff --git a/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h b/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h
index 83e25012baeff336b0d69fe4c51c54f72674c325..0e005ec44186e3ad4709d2a44cf0558d9b1944da 100644
--- a/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h
+++ b/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h
@@ -96,7 +96,8 @@ private:
     };
 
     bool isTimelineRunning() const;
-    void scheduleAnimationFrame(SMILTime fireTime);
+    void synchronizeToDocumentTimeline();
+    void scheduleAnimationFrame(double delayTime);
     void cancelAnimationFrame();
     void wakeupTimerFired(TimerBase*);
     void scheduleAnimationPolicyTimer();
@@ -111,19 +112,20 @@ private:
     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.

[pdr., 2016/08/18 19:50:06]

We mix "start" and "begin" here. Wdyt about m_hasBegun/hasBegun(), or start()
instead of begin()?

[fs, 2016/08/18 20:34:32]

I guess begin, and variants thereof, would be more SMILy (it refers to this as
"document begin"). I think I prefer 'start' a little bit though (and that's
probably a smaller incremental change), so unless you have a strong opinion I
might go with that. Will decide tomorrow though =)

[fs, 2016/08/19 11:11:24]

I ended up going with begin() -> start().

+    bool m_paused; // The timeline is paused.
+
     bool m_documentOrderIndexesDirty;
 
     Timer<SMILTimeContainer> m_wakeupTimer;