Update V8 DEPS.

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/579c986..2f38df6

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

Change-Id: I0ffc30c9d1a4ee518fa9073e17c614902d70e6ad
Reviewed-on: https://chromium-review.googlesource.com/1137850Reviewed-by: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#54448}

DEPS

@@ -16,7 +16,7 @@ deps = {
   'v8/tools/gyp':
     Var('chromium_url') + '/external/gyp.git' + '@' + 'd61a9397e668fa9843c4aa7da9e79460fe590bfb',
   'v8/third_party/depot_tools':
-    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '579c98612b6ff77608ecb5fdebc40276b371ddd9',
+    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '2f38df65f95e1e65f276f9bd654b8a98109e6c95',
   'v8/third_party/icu':
     Var('chromium_url') + '/chromium/deps/icu.git' + '@' + 'a9a2bd3ee4f1d313651c5272252aaf2a3e7ed529',
   'v8/third_party/instrumented_libraries':