Add component for feature engagement tracking.

components/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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//printing/features/features.gni")
 import("//rlz/features/features.gni")
 import("//testing/test.gni")
@@ skipping 225 matching lines @@
   if (is_ios) {
     deps += [ ":components_tests_pak_bundle_data" ]
   }
 
   if (is_mac || is_linux) {
     data_deps += [ "//content/shell:pak" ]
   }
 
   if (is_android) {
     deps += [
+      "//components/feature_engagement_tracker:unit_tests",
       "//components/gcm_driver/instance_id:test_support",
       "//components/gcm_driver/instance_id/android:instance_id_driver_java",
       "//components/gcm_driver/instance_id/android:instance_id_driver_test_support_java",
       "//components/invalidation/impl",
       "//components/invalidation/impl:java",
       "//components/policy/android:policy_java",
       "//components/safe_json",
       "//components/safe_json/android:safe_json_java",
       "//components/signin/core/browser",
       "//components/signin/core/browser/android:java",
@@ skipping 251 matching lines @@
       "//testing/perf",
       "//url",
     ]
 
     if (!is_ios) {
       sources += [ "discardable_memory/common/discardable_shared_memory_heap_perftest.cc" ]
       deps += [ "//components/discardable_memory/common" ]
     }
   }
 }