[TTS] Add aggregation of CTR metrics to the CS component.

components/contextual_search/BUILD.gn

 # Copyright 2015 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("//mojo/public/tools/bindings/mojom.gni")
 
 # GYP version: components/contextual_search.gypi:contextual_search_mojo_bindings
 mojom("mojo_bindings") {
   sources = [
     "common/contextual_search_js_api_service.mojom",
     "common/overlay_page_notifier_service.mojom",
   ]
 
   use_new_wrapper_types = false
 }
 
 # GYP version: components/contextual_search.gypi:contextual_search_browser
 static_library("browser") {
   sources = [
     "browser/contextual_search_js_api_service_impl.cc",
     "browser/contextual_search_js_api_service_impl.h",
+    "browser/ctr_aggregator.cc",
+    "browser/ctr_aggregator.h",
+    "browser/native_int_storage.h",
   ]
   deps = [
     ":mojo_bindings",
     "//base",
   ]
 }
 
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "browser/ctr_aggregator_unittest.cc",
+  ]
+
+  deps = [
+    ":browser",
+    "//testing/gtest",
+  ]
+}
+
 # GYP version: components/contextual_search.gypi:contextual_search_renderer
 static_library("renderer") {
   sources = [
     "renderer/contextual_search_wrapper.cc",
     "renderer/contextual_search_wrapper.h",
     "renderer/overlay_js_render_frame_observer.cc",
     "renderer/overlay_js_render_frame_observer.h",
     "renderer/overlay_page_notifier_service_impl.cc",
     "renderer/overlay_page_notifier_service_impl.h",
   ]
   deps = [
     ":mojo_bindings",
     "//base",
     "//content/public/common",
     "//content/public/renderer",
     "//gin",
     "//mojo/public/cpp/bindings",
     "//services/shell/public/cpp",
     "//third_party/WebKit/public:blink_headers",
     "//v8",
   ]
 }