[Sync] Remove unneeded 'using syncer::' lines and 'syncer::' scopings

sync/notifier/non_blocking_invalidation_notifier_unittest.cc

Index: sync/notifier/non_blocking_invalidation_notifier_unittest.cc
diff --git a/sync/notifier/non_blocking_invalidation_notifier_unittest.cc b/sync/notifier/non_blocking_invalidation_notifier_unittest.cc
index bd8ccebbb52c713578295355bc61952fb9c0a4a4..7a30f585fe48e5e4391fcfbf894ce3bd37b2295d 100644
--- a/sync/notifier/non_blocking_invalidation_notifier_unittest.cc
+++ b/sync/notifier/non_blocking_invalidation_notifier_unittest.cc
@@ -43,8 +43,7 @@ class NonBlockingInvalidationNotifierTest : public testing::Test {
             notifier_options,
             InvalidationVersionMap(),
             std::string(),  // initial_invalidation_state
-            syncer::MakeWeakHandle(
-                base::WeakPtr<syncer::InvalidationStateTracker>()),
+            MakeWeakHandle(base::WeakPtr<InvalidationStateTracker>()),
             "fake_client_info"));
     invalidation_notifier_->AddObserver(&mock_observer_);
   }
@@ -68,10 +67,10 @@ class NonBlockingInvalidationNotifierTest : public testing::Test {
 TEST_F(NonBlockingInvalidationNotifierTest, Basic) {
   InSequence dummy;
 
-  syncer::ModelTypePayloadMap type_payloads;
-  type_payloads[syncer::PREFERENCES] = "payload";
-  type_payloads[syncer::BOOKMARKS] = "";
-  type_payloads[syncer::AUTOFILL] = "";
+  ModelTypePayloadMap type_payloads;
+  type_payloads[PREFERENCES] = "payload";
+  type_payloads[BOOKMARKS] = "";
+  type_payloads[AUTOFILL] = "";
 
   EXPECT_CALL(mock_observer_, OnNotificationsEnabled());
   EXPECT_CALL(mock_observer_,