Added default timeout to InstrumentedHttp

BUG=

Review URL: https://codereview.chromium.org/1512643002

Cr-Mirrored-From: https://chromium.googlesource.com/infra/infra
Cr-Mirrored-Commit: 637ea74ee47615fc471d592613d046ba0a5c3bd6
1 file changed