Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/68bf4b8..6705895

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

Change-Id: Id30b10fbbbe7d29edb71f08d02e9641ae777f52a
Reviewed-on: https://chromium-review.googlesource.com/1172151
Commit-Queue: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Reviewed-by: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#55073}

DEPS

@@ -13,7 +13,7 @@ vars = {
 
 deps = {
   'v8/build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '68bf4b893087c4f85bff4c0a12effe306bfe2e08',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + '67058958495f04cf8d1af5a6a355530e0a422efc',
   'v8/tools/gyp':
     Var('chromium_url') + '/external/gyp.git' + '@' + 'd61a9397e668fa9843c4aa7da9e79460fe590bfb',
   'v8/third_party/depot_tools':