diff -r 000000000000 -r 6474c204b198 dom/smil/nsSMILInterval.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/smil/nsSMILInterval.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,85 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NS_SMILINTERVAL_H_
+#define NS_SMILINTERVAL_H_
+
+#include "nsSMILInstanceTime.h"
+#include "nsTArray.h"
+
+//----------------------------------------------------------------------
+// nsSMILInterval class
+//
+// A structure consisting of a begin and end time. The begin time must be
+// resolved (i.e. not indefinite or unresolved).
+//
+// For an overview of how this class is related to other SMIL time classes see
+// the documentation in nsSMILTimeValue.h
+
+class nsSMILInterval
+{
+public:
+  nsSMILInterval();
+  nsSMILInterval(const nsSMILInterval& aOther);
+  ~nsSMILInterval();
+  void Unlink(bool aFiltered = false);
+
+  const nsSMILInstanceTime* Begin() const
+  {
+    NS_ABORT_IF_FALSE(mBegin && mEnd,
+        "Requesting Begin() on un-initialized instance time");
+    return mBegin;
+  }
+  nsSMILInstanceTime* Begin();
+
+  const nsSMILInstanceTime* End() const
+  {
+    NS_ABORT_IF_FALSE(mBegin && mEnd,
+        "Requesting End() on un-initialized instance time");
+    return mEnd;
+  }
+  nsSMILInstanceTime* End();
+
+  void SetBegin(nsSMILInstanceTime& aBegin);
+  void SetEnd(nsSMILInstanceTime& aEnd);
+  void Set(nsSMILInstanceTime& aBegin, nsSMILInstanceTime& aEnd)
+  {
+    SetBegin(aBegin);
+    SetEnd(aEnd);
+  }
+
+  void FixBegin();
+  void FixEnd();
+
+  typedef nsTArray<nsRefPtr<nsSMILInstanceTime> > InstanceTimeList;
+
+  void AddDependentTime(nsSMILInstanceTime& aTime);
+  void RemoveDependentTime(const nsSMILInstanceTime& aTime);
+  void GetDependentTimes(InstanceTimeList& aTimes);
+
+  // Cue for assessing if this interval can be filtered
+  bool IsDependencyChainLink() const;
+
+private:
+  nsRefPtr<nsSMILInstanceTime> mBegin;
+  nsRefPtr<nsSMILInstanceTime> mEnd;
+
+  // nsSMILInstanceTimes to notify when this interval is changed or deleted.
+  InstanceTimeList mDependentTimes;
+
+  // Indicates if the end points of the interval are fixed or not.
+  //
+  // Note that this is not the same as having an end point whose TIME is fixed
+  // (i.e. nsSMILInstanceTime::IsFixed() returns true). This is because it is
+  // possible to have an end point with a fixed TIME and yet still update the
+  // end point to refer to a different nsSMILInstanceTime object.
+  //
+  // However, if mBegin/EndFixed is true, then BOTH the nsSMILInstanceTime
+  // OBJECT returned for that end point and its TIME value will not change.
+  bool mBeginFixed;
+  bool mEndFixed;
+};
+
+#endif // NS_SMILINTERVAL_H_