Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/1caa03d..2fb6537

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

Change-Id: I68d342787770515ebbd38b81c341202026b24a25
Reviewed-on: https://chromium-review.googlesource.com/c/1341462Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#57591}

DEPS

@@ -13,7 +13,7 @@ vars = {
 
 deps = {
   'v8/build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '1caa03da844c72496e733bd51570eb1467b9b37c',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + '2fb6537bf59c9c9a736997b8bd888ca0ecf54322',
   'v8/third_party/depot_tools':
     Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + 'c6ffd7af7d84ec354a92a0dc11613ec23cf82c60',
   'v8/third_party/icu':