Update V8 DEPS.
Update V8 DEPS.

Rolling v8/build/gyp to 34640080d08ab2a37665512e52142947def3056d

Rolling v8/tools/clang to f6daa55d03995e82201a3278203e7c0421a59546

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/937063002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#26732}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh