[Easy Unlock] Add a convenience test target for rapid iteration.

components/proximity_auth/BUILD.gn

 # Copyright 2014 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.
 
 static_library("proximity_auth") {
   sources = [
     "bluetooth_util.cc",
     "bluetooth_util_chromeos.cc",
     "bluetooth_util.h",
     "connection.cc",
@@ skipping 20 matching lines @@
     "wire_message_unittest.cc",
   ]
 
   deps = [
     ":proximity_auth",
     "//base/test:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
+
+# Note: This is a convenience target for ease of rapid iteration during
+# development. It is not executed on any try or build bots.
+test("proximity_auth_unittests") {
+  sources = [
+    "run_all_unittests.cc",
+  ]
+  
+  deps = [
+    ":unit_tests",
+  ]
+}