cmd/pprof: use proxy from environment

See #18736

Change-Id: I9c16357c05c16db677125d3077ee466b71559c7a
Reviewed-on: https://go-review.googlesource.com/38343Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/pprof/pprof.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	"cmd/internal/objfile"
+
 	"github.com/google/pprof/driver"
 	"github.com/google/pprof/profile"
 )
@@ -72,7 +73,8 @@ func getProfile(source string, timeout time.Duration) (*profile.Profile, error)
 	client := &http.Client{
 		Transport: &http.Transport{
 			ResponseHeaderTimeout: timeout + 5*time.Second,
-			TLSClientConfig:       tlsConfig,
+			Proxy:           http.ProxyFromEnvironment,
+			TLSClientConfig: tlsConfig,
 		},
 	}
 	resp, err := client.Get(source)