Revert "Version bump to etcd v3.2.11, grpc v1.7.5"

vendor/github.com/cockroachdb/cmux/buffer.go

@@ -1,35 +0,0 @@
-package cmux
-
-import (
-	"bytes"
-	"io"
-)
-
-// bufferedReader is an optimized implementation of io.Reader that behaves like
-// ```
-// io.MultiReader(bytes.NewReader(buffer.Bytes()), io.TeeReader(source, buffer))
-// ```
-// without allocating.
-type bufferedReader struct {
-	source     io.Reader
-	buffer     *bytes.Buffer
-	bufferRead int
-	bufferSize int
-}
-
-func (s *bufferedReader) Read(p []byte) (int, error) {
-	// Functionality of bytes.Reader.
-	bn := copy(p, s.buffer.Bytes()[s.bufferRead:s.bufferSize])
-	s.bufferRead += bn
-
-	p = p[bn:]
-
-	// Funtionality of io.TeeReader.
-	sn, sErr := s.source.Read(p)
-	if sn > 0 {
-		if wn, wErr := s.buffer.Write(p[:sn]); wErr != nil {
-			return bn + wn, wErr
-		}
-	}
-	return bn + sn, sErr
-}