Add //chromeos GN target.

This CL depends on https://codereview.chromium.org/637643003/

BUG=None
[email protected], [email protected]
[email protected], [email protected], [email protected], [email protected]
TEST=chromeos_unittests / ash_shell works

Review URL: https://codereview.chromium.org/637093002

Cr-Commit-Position: refs/heads/master@{#298951}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 0fa6211b..af3c9e6 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -853,7 +853,7 @@
       "chromeos/system/fake_input_device_settings.h",
     ]
     configs += [ "//build/config/linux:dbus" ]
-    #deps += [ "//chromeos:test_support" ]  TODO(GYP)
+    deps += [ "//chromeos:test_support" ]
   }
 
   if (enable_configuration_policy) {