Export stability metrics to UMA from Blimp engine

blimp/engine/app/blimp_metrics_service_client_unittest.cc

Index: blimp/engine/app/blimp_metrics_service_client_unittest.cc
diff --git a/blimp/engine/app/blimp_metrics_service_client_unittest.cc b/blimp/engine/app/blimp_metrics_service_client_unittest.cc
index f773e14ab6207ab74594193103da15b6bcde568f..23ad0f8c1131af2cd5f3924302fc0f7a1f420757 100644
--- a/blimp/engine/app/blimp_metrics_service_client_unittest.cc
+++ b/blimp/engine/app/blimp_metrics_service_client_unittest.cc
@@ -8,15 +8,17 @@
 #include <string>
 
 #include "base/memory/ref_counted.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/test/test_simple_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/metrics/metrics_service.h"
+#include "components/metrics/stability_metrics_helper.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/in_memory_pref_store.h"
 #include "components/prefs/pref_service.h"
 #include "components/prefs/pref_service_factory.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "net/url_request/url_request_test_util.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -37,23 +39,27 @@ class BlimpMetricsServiceClientTest : public testing::Test {
 
  protected:
   void SetUp() override {
-    // Set up PrefRegistry
+    // Set up NotificationService for StabilityMetricsHelper to use.
+    notification_service_.reset(content::NotificationService::Create());
+
+    // Set up PrefRegistry.
     pref_registry_ = new user_prefs::PrefRegistrySyncable();
     metrics::MetricsService::RegisterPrefs(pref_registry_.get());
+    metrics::StabilityMetricsHelper::RegisterPrefs(pref_registry_.get());
 
-    // Set up PrefService
+    // Set up PrefService.
     PrefServiceFactory pref_service_factory;
     pref_service_factory.set_user_prefs(new InMemoryPrefStore());
     pref_service_factory.set_read_error_callback(base::Bind(&HandleReadError));
     pref_service_ = pref_service_factory.Create(pref_registry_.get());
     ASSERT_NE(nullptr, pref_service_.get());
 
-    // Set up RequestContextGetter
+    // Set up RequestContextGetter.
     request_context_getter_ = new net::TestURLRequestContextGetter(
         base::ThreadTaskRunnerHandle::Get());
 
-    // Set task runner global for MetricsService
-    base::SetRecordActionTaskRunner(message_loop_.task_runner());
+    // Set task runner global for MetricsService.
+    base::SetRecordActionTaskRunner(base::ThreadTaskRunnerHandle::Get());
 
     // Set up BlimpMetricsServiceClient
     client_.reset(new BlimpMetricsServiceClient(pref_service_.get(),
@@ -88,7 +94,8 @@ class BlimpMetricsServiceClientTest : public testing::Test {
   }
 
  private:
-  base::MessageLoop message_loop_;
+  content::TestBrowserThreadBundle thread_bundle_;
+  std::unique_ptr<content::NotificationService> notification_service_;
   scoped_refptr<user_prefs::PrefRegistrySyncable> pref_registry_;
   std::unique_ptr<PrefService> pref_service_;
   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;