Bug 1267510 part 2 - Add origin time invariant to DocumentTimeline. r=birtles

MozReview-Commit-ID: Kf7PzzAH9Tj

--HG--
extra : rebase_source : 1cb1ff9f06c778d55f8a4a6beedccba946a31fbc

dom/animation/DocumentTimeline.cpp

@@ -88,7 +88,9 @@ DocumentTimeline::ToTimelineTime(const TimeStamp& aTimeStamp) const
     return result;
   }
 
-  result.SetValue(aTimeStamp - timing->GetNavigationStartTimeStamp());
+  result.SetValue(aTimeStamp
+                  - timing->GetNavigationStartTimeStamp()
+                  - mOriginTime);
   return result;
 }
 
@@ -204,7 +206,7 @@ DocumentTimeline::ToTimeStamp(const TimeDuration& aTimeDuration) const
     return result;
   }
 
-  result = timing->GetNavigationStartTimeStamp() + aTimeDuration;
+  result = timing->GetNavigationStartTimeStamp() + aTimeDuration + mOriginTime;
   return result;
 }
 

dom/animation/DocumentTimeline.h

@@ -28,10 +28,11 @@ class DocumentTimeline final
   , public nsARefreshObserver
 {
 public:
-  explicit DocumentTimeline(nsIDocument* aDocument)
+  DocumentTimeline(nsIDocument* aDocument, const TimeDuration& aOriginTime)
     : AnimationTimeline(aDocument->GetParentObject())
     , mDocument(aDocument)
     , mIsObservingRefreshDriver(false)
+    , mOriginTime(aOriginTime)
   {
   }
 
@@ -84,6 +85,8 @@ protected:
   // iframe).
   mutable TimeStamp mLastRefreshDriverTime;
   bool mIsObservingRefreshDriver;
+
+  TimeDuration mOriginTime;
 };
 
 } // namespace dom

dom/base/nsDocument.cpp

@@ -3241,7 +3241,7 @@ DocumentTimeline*
 nsDocument::Timeline()
 {
   if (!mDocumentTimeline) {
-    mDocumentTimeline = new DocumentTimeline(this);
+    mDocumentTimeline = new DocumentTimeline(this, TimeDuration(0));
   }
 
   return mDocumentTimeline;