Use faster zlib implementation.
Use faster zlib implementation.

R=maruel@chromium.org, vadimsh@chromium.org
BUG=
CQ_INCLUDE_TRYBOTS=tryserver.infra:Luci-go Linux Trusty 64 Tester,Luci-go Linux Precise 32 Tester,Luci-go Win Tester,Luci-go Mac Tester

Review URL: https://codereview.chromium.org/1255413007 .

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go