Update vendored libs

vendor/github.com/prometheus/common/expfmt/decode.go

@@ -14,7 +14,6 @@
 package expfmt
 
 import (
-	"bufio"
 	"fmt"
 	"io"
 	"math"
@@ -22,8 +21,8 @@ import (
 	"net/http"
 
 	dto "github.com/prometheus/client_model/go"
-	"google.golang.org/protobuf/encoding/protodelim"
 
+	"github.com/matttproud/golang_protobuf_extensions/pbutil"
 	"github.com/prometheus/common/model"
 )
 
@@ -45,7 +44,7 @@ func ResponseFormat(h http.Header) Format {
 
 	mediatype, params, err := mime.ParseMediaType(ct)
 	if err != nil {
-		return fmtUnknown
+		return FmtUnknown
 	}
 
 	const textType = "text/plain"
@@ -53,44 +52,42 @@ func ResponseFormat(h http.Header) Format {
 	switch mediatype {
 	case ProtoType:
 		if p, ok := params["proto"]; ok && p != ProtoProtocol {
-			return fmtUnknown
+			return FmtUnknown
 		}
 		if e, ok := params["encoding"]; ok && e != "delimited" {
-			return fmtUnknown
+			return FmtUnknown
 		}
-		return fmtProtoDelim
+		return FmtProtoDelim
 
 	case textType:
 		if v, ok := params["version"]; ok && v != TextVersion {
-			return fmtUnknown
+			return FmtUnknown
 		}
-		return fmtText
+		return FmtText
 	}
 
-	return fmtUnknown
+	return FmtUnknown
 }
 
 // NewDecoder returns a new decoder based on the given input format.
 // If the input format does not imply otherwise, a text format decoder is returned.
 func NewDecoder(r io.Reader, format Format) Decoder {
-	switch format.FormatType() {
-	case TypeProtoDelim:
-		return &protoDecoder{r: bufio.NewReader(r)}
+	switch format {
+	case FmtProtoDelim:
+		return &protoDecoder{r: r}
 	}
 	return &textDecoder{r: r}
 }
 
 // protoDecoder implements the Decoder interface for protocol buffers.
 type protoDecoder struct {
-	r protodelim.Reader
+	r io.Reader
 }
 
 // Decode implements the Decoder interface.
 func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
-	opts := protodelim.UnmarshalOptions{
-		MaxSize: -1,
-	}
-	if err := opts.UnmarshalFrom(d.r, v); err != nil {
+	_, err := pbutil.ReadDelimited(d.r, v)
+	if err != nil {
 		return err
 	}
 	if !model.IsValidMetricName(model.LabelValue(v.GetName())) {
@@ -135,10 +132,7 @@ func (d *textDecoder) Decode(v *dto.MetricFamily) error {
 	}
 	// Pick off one MetricFamily per Decode until there's nothing left.
 	for key, fam := range d.fams {
-		v.Name = fam.Name
-		v.Help = fam.Help
-		v.Type = fam.Type
-		v.Metric = fam.Metric
+		*v = *fam
 		delete(d.fams, key)
 		return nil
 	}