GRC: Added Tab coordination units behind a feature flag

services/resource_coordinator/public/cpp/resource_coordinator_features.cc

Index: services/resource_coordinator/public/cpp/resource_coordinator_features.cc
diff --git a/services/resource_coordinator/public/cpp/resource_coordinator_features.cc b/services/resource_coordinator/public/cpp/resource_coordinator_features.cc
new file mode 100644
index 0000000000000000000000000000000000000000..076376223f008faad4d20380cd9163bc634943e0
--- /dev/null
+++ b/services/resource_coordinator/public/cpp/resource_coordinator_features.cc
@@ -0,0 +1,13 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "services/resource_coordinator/public/cpp/resource_coordinator_features.h"
+
+namespace features {
+
+// Globally enable the GRC.
+const base::Feature kGlobalResourceCoordinator{
+    "GlobalResourceCoordinator", base::FEATURE_DISABLED_BY_DEFAULT};
+
+}  // namespace features