Propagate return code from grit tool

Without this the outputs list verification failure doesn't cause build
to fail.

R=agrieve@chromium.org

Change-Id: I5c7416c3ff1681aab0f171ef3ee608aece130e8a
Reviewed-on: https://chromium-review.googlesource.com/c/1309781Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604597}

tools/grit/grit.py

@@ -12,4 +12,4 @@ import grit.grit_runner
 
 
 if __name__ == '__main__':
-  grit.grit_runner.Main(sys.argv[1:])
+  sys.exit(grit.grit_runner.Main(sys.argv[1:]))

tools/grit/grit/grit_runner.py

@@ -244,9 +244,9 @@ def Main(args):
     if options.profile_dest:
       import hotshot
       prof = hotshot.Profile(options.profile_dest)
-      prof.runcall(toolobject.Run, options, args[1:])
+      return prof.runcall(toolobject.Run, options, args[1:])
     else:
-      toolobject.Run(options, args[1:])
+      return toolobject.Run(options, args[1:])
 
 
 if __name__ == '__main__':