Merge pull request #12839 from prometheus/beorn7/histogram

storage: remove obsolete TODO

storage/buffer.go

@@ -42,7 +42,6 @@ func NewBuffer(delta int64) *BufferedSeriesIterator {
 // NewBufferIterator returns a new iterator that buffers the values within the
 // time range of the current element and the duration of delta before.
 func NewBufferIterator(it chunkenc.Iterator, delta int64) *BufferedSeriesIterator {
-	// TODO(codesome): based on encoding, allocate different buffer.
 	bit := &BufferedSeriesIterator{
 		buf:   newSampleRing(delta, 0, chunkenc.ValNone),
 		delta: delta,