Rolling v8/build/gyp to 3f21260b43401553c37bb28090b65a75577d5b4e

Rolling v8/tools/swarming_client to b64f0423ee66e730b0ceb88de8b9b89a98d7b61a

TBR=machenbach@chromium.org,vogelheim@chromium.org,hablich@chromium.org

Review URL: https://codereview.chromium.org/1417863002

Cr-Commit-Position: refs/heads/master@{#31429}