Create and integrate a metrics service client into Blimp engine.

blimp/engine/app/blimp_metrics_service_client_unittest.cc

+// Copyright 2016 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 "blimp/engine/app/blimp_metrics_service_client.h"
+
+#include <list>
+#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/thread_task_runner_handle.h"
+#include "components/metrics/metrics_service.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 "net/url_request/url_request_context_getter.h"
+#include "net/url_request/url_request_test_util.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace blimp {
+namespace engine {
+// Shows notifications which correspond to PersistentPrefStore's reading errors.
+void HandleReadError(PersistentPrefStore::PrefReadError error) {

[Bernhard Bauer, 2016/05/11 08:53:14]

Put this into an anonymous namespace?

[Jess, 2016/05/11 17:07:25]

Done.

+}
+
+class BlimpMetricsServiceClientTest : public testing::Test {
+ protected:
+  void SetUp() override;

[Kevin M, 2016/05/11 17:08:42]

optional nit: since this is in a .cc file, you can inline the implementation in
the class definition if you prefer.

[Jess, 2016/05/11 20:17:30]

Done.

+  void TearDown() override;
+
+  void SetUpPrefRegistry();

[Kevin M, 2016/05/11 17:08:42]

nit: Can you just merge these into commented regions of SetUp()? SetUp is the
only caller of these functions.

[Jess, 2016/05/11 20:17:30]

Done.

+  void SetUpPrefService();
+  void SetUpRequestContextGetter();
+
+  base::MessageLoop message_loop_;
+  scoped_refptr<user_prefs::PrefRegistrySyncable> pref_registry_;
+  std::unique_ptr<PrefService> pref_service_;
+  scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
+  std::unique_ptr<BlimpMetricsServiceClient> client_;

[Kevin M, 2016/05/11 17:08:42]

DISALLOW_COPY_AND_ASSIGN(...);

[Jess, 2016/05/11 20:17:30]

Done.

+};
+
+void BlimpMetricsServiceClientTest::SetUp() {
+  // Set up all deps and then InitializeBlimpMetrics.
+  SetUpPrefRegistry();
+  SetUpPrefService();
+  SetUpRequestContextGetter();
+  base::SetRecordActionTaskRunner(message_loop_.task_runner());
+  client_.reset(new BlimpMetricsServiceClient(pref_service_.get(),
+                                              request_context_getter_));
+  base::RunLoop().RunUntilIdle();
+
+  // Checks of InitializeBlimpMetrics.
+  // TODO(jessicag): Check request_context_getter_ set.
+  // PrefService unique pointer set up by BlimpMetricsServiceClient.
+  EXPECT_EQ(PrefService::INITIALIZATION_STATUS_SUCCESS,
+            pref_service_->GetInitializationStatus());
+
+  // TODO(jessicag): Confirm registration of metrics providers.
+  // TODO(jessicag): MetricsService initializes recording state.
+  // TODO(jessicag): Confirm MetricsService::Start() is called.
+}
+
+void BlimpMetricsServiceClientTest::TearDown() {
+  // Trigger BlimpMetricsServiceClientTest destructor.
+  client_.reset();
+  ASSERT_EQ(nullptr, client_.get());
+  base::RunLoop().RunUntilIdle();
+  // TODO(jessicag): Ensure MetricsService::Stop() is called.
+
+  // PrefService unaffected
+  EXPECT_EQ(PrefService::INITIALIZATION_STATUS_SUCCESS,
+            pref_service_->GetInitializationStatus());
+
+  // Clean up static variable in MetricService to avoid impacting other tests.
+  metrics::MetricsService::SetExecutionPhase(
+      metrics::MetricsService::UNINITIALIZED_PHASE,
+      pref_service_.get());
+}
+
+void BlimpMetricsServiceClientTest::SetUpPrefRegistry() {
+  pref_registry_ = new user_prefs::PrefRegistrySyncable();
+  metrics::MetricsService::RegisterPrefs(pref_registry_.get());
+}
+
+void BlimpMetricsServiceClientTest::SetUpPrefService() {
+  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());
+}
+
+void BlimpMetricsServiceClientTest::SetUpRequestContextGetter() {
+  request_context_getter_ =
+      new net::TestURLRequestContextGetter(base::ThreadTaskRunnerHandle::Get());
+}
+
+TEST_F(BlimpMetricsServiceClientTest, CtorDtor) {
+  // Confirm construction and destruction work as expected.
+}
+
+}  // namespace engine
+}  // namespace blimp