--- a/dom/media/MediaSegment.h
+++ b/dom/media/MediaSegment.h
@@ -279,16 +279,36 @@ public:
     void Next() { ++mIndex; }
     const Chunk& operator*() { return mSegment.mChunks[mIndex]; }
     const Chunk* operator->() { return &mSegment.mChunks[mIndex]; }
   private:
     const MediaSegmentBase<C, Chunk>& mSegment;
     uint32_t mIndex;
   };
 
+  Chunk* FindChunkContaining(StreamTime aOffset, StreamTime* aStart = nullptr)
+  {
+    if (aOffset < 0) {
+      return nullptr;
+    }
+    StreamTime offset = 0;
+    for (uint32_t i = 0; i < mChunks.Length(); ++i) {
+      Chunk& c = mChunks[i];
+      StreamTime nextOffset = offset + c.GetDuration();
+      if (aOffset < nextOffset) {
+        if (aStart) {
+          *aStart = offset;
+        }
+        return &c;
+      }
+      offset = nextOffset;
+    }
+    return nullptr;
+  }
+
   void RemoveLeading(StreamTime aDuration)
   {
     RemoveLeading(aDuration, 0);
   }
 
 #ifdef MOZILLA_INTERNAL_API
   void GetStartTime(TimeStamp &aTime) {
     aTime = mChunks[0].mTimeStamp;
@@ -351,36 +371,16 @@ protected:
   {
     MOZ_ASSERT(aDuration >= 0);
     Chunk* c = mChunks.AppendElement();
     c->mDuration = aDuration;
     mDuration += aDuration;
     return c;
   }
 
-  Chunk* FindChunkContaining(StreamTime aOffset, StreamTime* aStart = nullptr)
-  {
-    if (aOffset < 0) {
-      return nullptr;
-    }
-    StreamTime offset = 0;
-    for (uint32_t i = 0; i < mChunks.Length(); ++i) {
-      Chunk& c = mChunks[i];
-      StreamTime nextOffset = offset + c.GetDuration();
-      if (aOffset < nextOffset) {
-        if (aStart) {
-          *aStart = offset;
-        }
-        return &c;
-      }
-      offset = nextOffset;
-    }
-    return nullptr;
-  }
-
   Chunk* GetLastChunk()
   {
     if (mChunks.IsEmpty()) {
       return nullptr;
     }
     return &mChunks[mChunks.Length() - 1];
   }