Don't download goma binaries during the cros-simplechrome DEPS hook.

Bug: 828392
Change-Id: Iddc8ad3d6501b981e39e6569c5e6e3dbfbed5e31
Reviewed-on: https://chromium-review.googlesource.com/998335
Commit-Queue: Benjamin Pastene <bpastene@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548857}

DEPS

@@ -1927,7 +1927,7 @@ hooks = [
     'action': [
       'src/third_party/chromite/bin/cros',
       'chrome-sdk',
-      '--nostart-goma',
+      '--nogoma',
       '--use-external-config',
       '--nogn-gen',
       '--download-vm',