Add unit test for ArcBluetoothBridge and TypeConverter

components/arc/BUILD.gn

Index: components/arc/BUILD.gn
diff --git a/components/arc/BUILD.gn b/components/arc/BUILD.gn
index 24975ca46dcfc21cce53aff39797e2e8595ad031..9a0d0e1a6ef97be5a507a9fc464948d0a316d8cf 100644
--- a/components/arc/BUILD.gn
+++ b/components/arc/BUILD.gn
@@ -175,6 +175,8 @@ static_library("arc_test_support") {
     "test/fake_arc_bridge_instance.h",
     "test/fake_arc_bridge_service.cc",
     "test/fake_arc_bridge_service.h",
+    "test/fake_bluetooth_instance.cc",
+    "test/fake_bluetooth_instance.h",
     "test/fake_notifications_instance.cc",
     "test/fake_notifications_instance.h",
     "test/fake_policy_instance.cc",
@@ -194,6 +196,8 @@ source_set("unit_tests") {
   testonly = true
   sources = [
     "arc_bridge_service_unittest.cc",
+    "bluetooth/arc_bluetooth_bridge_unittest.cc",
+    "bluetooth/bluetooth_type_converters_unittest.cc",
     "ime/arc_ime_service_unittest.cc",
     "intent_helper/activity_icon_loader_unittest.cc",
     "intent_helper/arc_intent_helper_bridge_unittest.cc",