Run dbus_unittests serially.

Otherwise, they will conflict with each other over the ownership of the
test DBus service.

BUG=571274
TBR=hashimoto@chromium.org

Review URL: https://codereview.chromium.org/1547503002

Cr-Commit-Position: refs/heads/master@{#366466}


CrOS-Libchrome-Original-Commit: c4ce3bff96c0ed58d549627c2c2071f8971c7398
diff --git a/dbus/run_all_unittests.cc b/dbus/run_all_unittests.cc
index dac4a3c..a758d54 100644
--- a/dbus/run_all_unittests.cc
+++ b/dbus/run_all_unittests.cc
@@ -8,7 +8,7 @@
 
 int main(int argc, char** argv) {
   base::TestSuite test_suite(argc, argv);
-  return base::LaunchUnitTests(
+  return base::LaunchUnitTestsSerially(
       argc, argv,
       base::Bind(&base::TestSuite::Run, base::Unretained(&test_suite)));
 }