http2/hpack: remove unused pair function from package

Move it to a _test.go file instead.

After CL 43190, the pair function is no longer used by the hpack
package, so it can be removed from it. It's still used by tests.

This can help avoid future readers spending time on figuring out
why pair exists in package, but is not used. It can also reduce
chance of the pair function unintentionally being used in the
package (if that needs to happen explicitly, then pair can be
easily moved back to package).

Change-Id: I12ee9b46f57a522bd09e5d0ee22296df4dee1f35
Reviewed-on: https://go-review.googlesource.com/43851
Reviewed-by: Brad Fitzpatrick <[email protected]>
Run-TryBot: Brad Fitzpatrick <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>

Author: dmitshur

http2/hpack/hpack_test.go

@@ -648,6 +648,10 @@ func TestHuffmanFuzzCrash(t *testing.T) {
 	}
 }
 
+func pair(name, value string) HeaderField {
+	return HeaderField{Name: name, Value: value}
+}
+
 func dehex(s string) []byte {
 	s = strings.Replace(s, " ", "", -1)
 	s = strings.Replace(s, "\n", "", -1)

http2/hpack/tables.go

@@ -125,10 +125,6 @@ func (t *headerFieldTable) idToIndex(id uint64) uint64 {
 	return k + 1
 }
 
-func pair(name, value string) HeaderField {
-	return HeaderField{Name: name, Value: value}
-}
-
 // http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-07#appendix-B
 var staticTable = newStaticTable()
 var staticTableEntries = [...]HeaderField{