Rolling v8/build/gyp to 4cf07e8d616739f6484e46c9359b2a35196b2585

Rolling v8/buildtools to 2a9a29fbdc2170c25e5cc0f642213eb7b3e7bc98

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

Review URL: https://codereview.chromium.org/1917073004

Cr-Commit-Position: refs/heads/master@{#35783}