Add component for feature engagement tracking.

components/feature_engagement_tracker/internal/feature_engagement_tracker_impl_unittest.cc

Index: components/feature_engagement_tracker/internal/feature_engagement_tracker_impl_unittest.cc
diff --git a/components/feature_engagement_tracker/internal/feature_engagement_tracker_impl_unittest.cc b/components/feature_engagement_tracker/internal/feature_engagement_tracker_impl_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8b9aedc40d186718617282c9a4c6cb2f5e2f4a3c
--- /dev/null
+++ b/components/feature_engagement_tracker/internal/feature_engagement_tracker_impl_unittest.cc
@@ -0,0 +1,11 @@
+// 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 "components/feature_engagement_tracker/internal/feature_engagement_tracker_impl.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(FeatureEngagementTrackerImplTest, DummyTest) {
+  EXPECT_TRUE(true);
+}