Extract Profile-independent GCMService from GCMProfileService

chrome/browser/services/gcm/gcm_service_unittest.cc

+// 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.
+
+#include "chrome/browser/services/gcm/gcm_service.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/location.h"
+#include "base/run_loop.h"
+#include "base/strings/string_util.h"
+#include "chrome/browser/services/gcm/fake_gcm_client_factory.h"
+#include "chrome/browser/services/gcm/gcm_app_handler.h"
+#include "chrome/browser/services/gcm/gcm_client_factory.h"
+#include "chrome/browser/services/gcm/gcm_client_mock.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/test/test_browser_thread_bundle.h"
+#include "google_apis/gaia/fake_identity_provider.h"
+#include "google_apis/gaia/fake_oauth2_token_service.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "net/url_request/url_request_test_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace gcm {
+
+namespace {
+
+const char kTestAccountID1[] = "user1@example.com";
+const char kTestAccountID2[] = "user2@example.com";
+const char kTestAccountID3[] = "user3@example.com";
+const char kTestAppID1[] = "TestApp1";
+const char kTestAppID2[] = "TestApp2";
+const char kUserID1[] = "user1";
+const char kUserID2[] = "user2";
+
+void PumpUILoop() {
+  base::RunLoop().RunUntilIdle();
+}
+
+void PumpIOLoop() {
+  base::RunLoop run_loop;
+  content::BrowserThread::PostTaskAndReply(content::BrowserThread::IO,
+                                           FROM_HERE,
+                                           base::Bind(&base::DoNothing),
+                                           run_loop.QuitClosure());
+  run_loop.Run();
+}
+
+std::vector<std::string> ToSenderList(const std::string& sender_ids) {
+  std::vector<std::string> senders;
+  Tokenize(sender_ids, ",", &senders);
+  return senders;
+}
+
+class FakeGCMAppHandler : public GCMAppHandler {
+ public:
+  enum Event {
+    NO_EVENT,
+    MESSAGE_EVENT,
+    MESSAGES_DELETED_EVENT,
+    SEND_ERROR_EVENT
+  };
+
+  FakeGCMAppHandler();
+  virtual ~FakeGCMAppHandler();
+
+  const Event& received_event() const { return received_event_; }
+  const std::string& app_id() const { return app_id_; }
+  const GCMClient::IncomingMessage& message() const { return message_; }
+  const GCMClient::SendErrorDetails& send_error_details() const {
+    return send_error_details_;
+  }
+
+  void WaitForNotification();
+
+  // GCMAppHandler:
+  virtual void ShutdownHandler() OVERRIDE;
+  virtual void OnMessage(const std::string& app_id,
+                         const GCMClient::IncomingMessage& message) OVERRIDE;
+  virtual void OnMessagesDeleted(const std::string& app_id) OVERRIDE;
+  virtual void OnSendError(
+      const std::string& app_id,
+      const GCMClient::SendErrorDetails& send_error_details) OVERRIDE;
+
+ private:
+  void ClearResults();
+
+  scoped_ptr<base::RunLoop> run_loop_;
+
+  Event received_event_;
+  std::string app_id_;
+  GCMClient::IncomingMessage message_;
+  GCMClient::SendErrorDetails send_error_details_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeGCMAppHandler);
+};
+
+class TestGCMService : public GCMService {
+ public:
+  TestGCMService(
+      bool start_automatically,
+      scoped_ptr<IdentityProvider> identity_provider,
+      const scoped_refptr<net::URLRequestContextGetter>& request_context);
+  virtual ~TestGCMService();
+
+ protected:
+  // GCMService:
+  virtual bool ShouldStartAutomatically() const OVERRIDE;
+  virtual base::FilePath GetStorePath() const OVERRIDE;
+  virtual scoped_refptr<net::URLRequestContextGetter>
+      GetURLRequestContextGetter() const OVERRIDE;
+
+ private:
+  base::ScopedTempDir temp_dir_;
+  scoped_refptr<net::URLRequestContextGetter> request_context_;
+  const bool start_automatically_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestGCMService);
+};
+
+FakeGCMAppHandler::FakeGCMAppHandler() : received_event_(NO_EVENT) {
+}
+
+FakeGCMAppHandler::~FakeGCMAppHandler() {
+}
+
+void FakeGCMAppHandler::WaitForNotification() {
+  run_loop_.reset(new base::RunLoop);
+  run_loop_->Run();
+  run_loop_.reset();
+}
+
+void FakeGCMAppHandler::ShutdownHandler() {
+}
+
+void FakeGCMAppHandler::OnMessage(const std::string& app_id,
+                                  const GCMClient::IncomingMessage& message) {
+  ClearResults();
+  received_event_ = MESSAGE_EVENT;
+  app_id_ = app_id;
+  message_ = message;
+  if (run_loop_)
+    run_loop_->Quit();
+}
+
+void FakeGCMAppHandler::OnMessagesDeleted(const std::string& app_id) {
+  ClearResults();
+  received_event_ = MESSAGES_DELETED_EVENT;
+  app_id_ = app_id;
+  if (run_loop_)
+    run_loop_->Quit();
+}
+
+void FakeGCMAppHandler::OnSendError(
+    const std::string& app_id,
+    const GCMClient::SendErrorDetails& send_error_details) {
+  ClearResults();
+  received_event_ = SEND_ERROR_EVENT;
+  app_id_ = app_id;
+  send_error_details_ = send_error_details;
+  if (run_loop_)
+    run_loop_->Quit();
+}
+
+void FakeGCMAppHandler::ClearResults() {
+  received_event_ = NO_EVENT;
+  app_id_.clear();
+  message_ = GCMClient::IncomingMessage();
+  send_error_details_ = GCMClient::SendErrorDetails();
+}
+
+TestGCMService::TestGCMService(
+    bool start_automatically,
+    scoped_ptr<IdentityProvider> identity_provider,
+    const scoped_refptr<net::URLRequestContextGetter>& request_context)
+    : GCMService(identity_provider.Pass()),
+      request_context_(request_context),
+      start_automatically_(start_automatically) {
+  if (!temp_dir_.CreateUniqueTempDir())
+    ADD_FAILURE();
+}
+
+TestGCMService::~TestGCMService() {
+}
+
+bool TestGCMService::ShouldStartAutomatically() const {
+  return start_automatically_;
+}
+
+base::FilePath TestGCMService::GetStorePath() const {
+  return temp_dir_.path();
+}
+
+scoped_refptr<net::URLRequestContextGetter>
+TestGCMService::GetURLRequestContextGetter() const {
+  return request_context_;
+}
+
+}  // namespace
+
+class TestGCMServiceWrapper {
+ public:
+  enum WaitToFinish {
+    DO_NOT_WAIT,
+    WAIT
+  };
+
+  explicit TestGCMServiceWrapper(
+      const scoped_refptr<net::URLRequestContextGetter>& request_context);
+  ~TestGCMServiceWrapper();
+
+  TestGCMService* service() { return service_.get(); }
+  FakeGCMAppHandler* gcm_app_handler() { return gcm_app_handler_.get(); }
+  const std::string& registration_id() const { return registration_id_; }
+  GCMClient::Result registration_result() const { return registration_result_; }
+  const std::string& send_message_id() const { return send_message_id_; }
+  GCMClient::Result send_result() const { return send_result_; }
+  GCMClient::Result unregistration_result() const {
+    return unregistration_result_;
+  }
+
+  void ClearRegistrationResult();
+  void ClearUnregistrationResult();
+
+  bool ServiceHasAppHandlers() const;
+  GCMClientMock* GetGCMClient();
+
+  void CreateService(bool start_automatically,
+                     GCMClientMock::LoadingDelay gcm_client_loading_delay);
+
+  void SignIn(const std::string& account_id);
+  void SignOut();
+
+  void Register(const std::string& app_id,
+                const std::vector<std::string>& sender_ids,
+                WaitToFinish wait_to_finish);
+  void Send(const std::string& app_id,
+            const std::string& receiver_id,
+            const GCMClient::OutgoingMessage& message,
+            WaitToFinish wait_to_finish);
+  void Unregister(const std::string& app_id, WaitToFinish wait_to_finish);
+
+  void WaitForAsyncOperation();
+
+ private:
+  void RegisterCompleted(const std::string& registration_id,
+                         GCMClient::Result result);
+  void SendCompleted(const std::string& message_id, GCMClient::Result result);
+  void UnregisterCompleted(GCMClient::Result result);
+
+  scoped_refptr<net::URLRequestContextGetter> request_context_;
+  FakeOAuth2TokenService token_service_;
+  scoped_ptr<FakeIdentityProvider> identity_provider_owner_;
+  FakeIdentityProvider* identity_provider_;
+  scoped_ptr<TestGCMService> service_;
+  scoped_ptr<FakeGCMAppHandler> gcm_app_handler_;
+
+  base::Closure async_operation_completed_callback_;
+
+  std::string registration_id_;
+  GCMClient::Result registration_result_;
+  std::string send_message_id_;
+  GCMClient::Result send_result_;
+  GCMClient::Result unregistration_result_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestGCMServiceWrapper);
+};
+
+TestGCMServiceWrapper::TestGCMServiceWrapper(
+    const scoped_refptr<net::URLRequestContextGetter>& request_context)
+    : request_context_(request_context),
+      identity_provider_(NULL),
+      registration_result_(GCMClient::UNKNOWN_ERROR),
+      send_result_(GCMClient::UNKNOWN_ERROR),
+      unregistration_result_(GCMClient::UNKNOWN_ERROR) {
+  identity_provider_owner_.reset(new FakeIdentityProvider(&token_service_));
+  identity_provider_ = identity_provider_owner_.get();
+}
+
+TestGCMServiceWrapper::~TestGCMServiceWrapper() {
+  if (!service_)
+    return;
+
+  service_->ShutdownService();
+  service_.reset();
+  PumpIOLoop();
+}
+
+void TestGCMServiceWrapper::ClearRegistrationResult() {
+  registration_id_.clear();
+  registration_result_ = GCMClient::UNKNOWN_ERROR;
+}
+
+void TestGCMServiceWrapper::ClearUnregistrationResult() {
+  unregistration_result_ = GCMClient::UNKNOWN_ERROR;
+}
+
+bool TestGCMServiceWrapper::ServiceHasAppHandlers() const {
+  return !service_->app_handlers_.empty();
+}
+
+GCMClientMock* TestGCMServiceWrapper::GetGCMClient() {
+  return static_cast<GCMClientMock*>(service_->GetGCMClientForTesting());
+}
+
+void TestGCMServiceWrapper::CreateService(
+    bool start_automatically,
+    GCMClientMock::LoadingDelay gcm_client_loading_delay) {
+  service_.reset(new TestGCMService(
+      start_automatically,
+      identity_provider_owner_.PassAs<IdentityProvider>(),
+      request_context_));
+  service_->Initialize(scoped_ptr<GCMClientFactory>(
+      new FakeGCMClientFactory(gcm_client_loading_delay)));
+
+  gcm_app_handler_.reset(new FakeGCMAppHandler);
+  service_->AddAppHandler(kTestAppID1, gcm_app_handler_.get());
+  service_->AddAppHandler(kTestAppID2, gcm_app_handler_.get());
+}
+
+void TestGCMServiceWrapper::SignIn(const std::string& account_id) {
+  token_service_.AddAccount(account_id);
+  identity_provider_->LogIn(account_id);
+  PumpIOLoop();
+  PumpUILoop();
+}
+
+void TestGCMServiceWrapper::SignOut() {
+  identity_provider_->LogOut();
+  PumpIOLoop();
+  PumpUILoop();
+}
+
+void TestGCMServiceWrapper::Register(const std::string& app_id,
+                                     const std::vector<std::string>& sender_ids,
+                                     WaitToFinish wait_to_finish) {
+  base::RunLoop run_loop;
+  async_operation_completed_callback_ = run_loop.QuitClosure();
+  service_->Register(app_id,
+                     sender_ids,
+                     base::Bind(&TestGCMServiceWrapper::RegisterCompleted,
+                                base::Unretained(this)));
+  if (wait_to_finish == WAIT)
+    run_loop.Run();
+}
+
+void TestGCMServiceWrapper::Send(const std::string& app_id,
+                                 const std::string& receiver_id,
+                                 const GCMClient::OutgoingMessage& message,
+                                 WaitToFinish wait_to_finish) {
+  base::RunLoop run_loop;
+  async_operation_completed_callback_ = run_loop.QuitClosure();
+  service_->Send(app_id,
+                 receiver_id,
+                 message,
+                 base::Bind(&TestGCMServiceWrapper::SendCompleted,
+                            base::Unretained(this)));
+  if (wait_to_finish == WAIT)
+    run_loop.Run();
+}
+
+void TestGCMServiceWrapper::Unregister(const std::string& app_id,
+                                       WaitToFinish wait_to_finish) {
+  base::RunLoop run_loop;
+  async_operation_completed_callback_ = run_loop.QuitClosure();
+  service_->Unregister(app_id,
+                       base::Bind(&TestGCMServiceWrapper::UnregisterCompleted,
+                                  base::Unretained(this)));
+  if (wait_to_finish == WAIT)
+    run_loop.Run();
+}
+
+void TestGCMServiceWrapper::WaitForAsyncOperation() {
+  base::RunLoop run_loop;
+  async_operation_completed_callback_ = run_loop.QuitClosure();
+  run_loop.Run();
+}
+
+void TestGCMServiceWrapper::RegisterCompleted(
+    const std::string& registration_id,
+    GCMClient::Result result) {
+  registration_id_ = registration_id;
+  registration_result_ = result;
+  if (!async_operation_completed_callback_.is_null())
+    async_operation_completed_callback_.Run();
+}
+
+void TestGCMServiceWrapper::SendCompleted(const std::string& message_id,
+                                          GCMClient::Result result) {
+  send_message_id_ = message_id;
+  send_result_ = result;
+  if (!async_operation_completed_callback_.is_null())
+    async_operation_completed_callback_.Run();
+}
+
+void TestGCMServiceWrapper::UnregisterCompleted(GCMClient::Result result) {
+  unregistration_result_ = result;
+  if (!async_operation_completed_callback_.is_null())
+    async_operation_completed_callback_.Run();
+}
+
+class GCMServiceTest : public testing::Test {
+ protected:
+  GCMServiceTest();
+  virtual ~GCMServiceTest();
+
+  // testing::Test:
+  void SetUp() OVERRIDE;
+  void TearDown() OVERRIDE;
+
+  scoped_ptr<content::TestBrowserThreadBundle> thread_bundle_;
+  scoped_refptr<net::URLRequestContextGetter> request_context_;
+  scoped_ptr<TestGCMServiceWrapper> wrapper_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GCMServiceTest);
+};
+
+GCMServiceTest::GCMServiceTest() {
+}
+
+GCMServiceTest::~GCMServiceTest() {
+}
+
+void GCMServiceTest::SetUp() {
+  thread_bundle_.reset(new content::TestBrowserThreadBundle(
+      content::TestBrowserThreadBundle::REAL_IO_THREAD));
+  request_context_ = new net::TestURLRequestContextGetter(
+      content::BrowserThread::GetMessageLoopProxyForThread(
+          content::BrowserThread::IO));
+  wrapper_.reset(new TestGCMServiceWrapper(request_context_));
+}
+
+void GCMServiceTest::TearDown() {
+  wrapper_.reset();
+}
+
+TEST_F(GCMServiceTest, CreateGCMServiceBeforeSignIn) {
+  // Create CreateGMCService first.
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+  EXPECT_FALSE(wrapper_->service()->IsStarted());
+
+  // Sign in. This will kick off the check-in.
+  wrapper_->SignIn(kTestAccountID1);
+  EXPECT_TRUE(wrapper_->service()->IsStarted());
+}
+
+TEST_F(GCMServiceTest, CreateGCMServiceAfterSignIn) {
+  // Sign in. This will not initiate the check-in.
+  wrapper_->SignIn(kTestAccountID1);
+
+  // Create GCMeService after sign-in.
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+  EXPECT_TRUE(wrapper_->service()->IsStarted());
+}
+
+TEST_F(GCMServiceTest, Shutdown) {
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+  EXPECT_TRUE(wrapper_->ServiceHasAppHandlers());
+
+  wrapper_->service()->ShutdownService();
+  EXPECT_FALSE(wrapper_->ServiceHasAppHandlers());
+}
+
+TEST_F(GCMServiceTest, SignInAndSignOutUnderPositiveChannelSignal) {
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+
+  // GCMClient should be loaded.
+  EXPECT_TRUE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::LOADED, wrapper_->GetGCMClient()->status());
+
+  wrapper_->SignOut();
+
+  // GCMClient should be checked out.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::CHECKED_OUT, wrapper_->GetGCMClient()->status());
+}
+
+TEST_F(GCMServiceTest, SignInAndSignOutUnderNonPositiveChannelSignal) {
+  // Non-positive channel signal will prevent GCMClient from checking in during
+  // sign-in.
+  wrapper_->CreateService(false, GCMClientMock::NO_DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+
+  // GCMClient should not be loaded.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::UNINITIALIZED, wrapper_->GetGCMClient()->status());
+
+  wrapper_->SignOut();
+
+  // Check-out should still be performed.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::CHECKED_OUT, wrapper_->GetGCMClient()->status());
+}
+
+TEST_F(GCMServiceTest, SignOutAndThenSignIn) {
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+
+  // GCMClient should be loaded.
+  EXPECT_TRUE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::LOADED, wrapper_->GetGCMClient()->status());
+
+  wrapper_->SignOut();
+
+  // GCMClient should be checked out.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::CHECKED_OUT, wrapper_->GetGCMClient()->status());
+
+  // Sign-in with a different account.
+  wrapper_->SignIn(kTestAccountID2);
+
+  // GCMClient should be loaded again.
+  EXPECT_TRUE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::LOADED, wrapper_->GetGCMClient()->status());
+}
+
+TEST_F(GCMServiceTest, StopAndRestartGCM) {
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+
+  // GCMClient should be loaded.
+  EXPECT_TRUE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::LOADED, wrapper_->GetGCMClient()->status());
+
+  // Stops the GCM.
+  wrapper_->service()->Stop();
+  PumpIOLoop();
+  PumpUILoop();
+
+  // GCMClient should be stopped.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::STOPPED, wrapper_->GetGCMClient()->status());
+
+  // Restarts the GCM.
+  wrapper_->service()->Start();
+  PumpIOLoop();
+  PumpUILoop();
+
+  // GCMClient should be loaded.
+  EXPECT_TRUE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::LOADED, wrapper_->GetGCMClient()->status());
+
+  // Stops the GCM.
+  wrapper_->service()->Stop();
+  PumpIOLoop();
+  PumpUILoop();
+
+  // GCMClient should be stopped.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::STOPPED, wrapper_->GetGCMClient()->status());
+
+  // Sign out.
+  wrapper_->SignOut();
+
+  // GCMClient should be checked out.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::CHECKED_OUT, wrapper_->GetGCMClient()->status());
+}
+
+TEST_F(GCMServiceTest, RegisterWhenNotSignedIn) {
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_TRUE(wrapper_->registration_id().empty());
+  EXPECT_EQ(GCMClient::NOT_SIGNED_IN, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceTest, RegisterUnderNonPositiveChannelSignal) {
+  // Non-positive channel signal will prevent GCMClient from checking in during
+  // sign-in.
+  wrapper_->CreateService(false, GCMClientMock::NO_DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+
+  // GCMClient should not be checked in.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::UNINITIALIZED, wrapper_->GetGCMClient()->status());
+
+  // Invoking register will make GCMClient checked in.
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+
+  // GCMClient should be checked in.
+  EXPECT_TRUE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::LOADED, wrapper_->GetGCMClient()->status());
+
+  // Registration should succeed.
+  const std::string expected_registration_id =
+      GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids);
+  EXPECT_EQ(expected_registration_id, wrapper_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceTest, SendWhenNotSignedIn) {
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+
+  GCMClient::OutgoingMessage message;
+  message.id = "1";
+  message.data["key1"] = "value1";
+  wrapper_->Send(kTestAppID1, kUserID1, message, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_TRUE(wrapper_->send_message_id().empty());
+  EXPECT_EQ(GCMClient::NOT_SIGNED_IN, wrapper_->send_result());
+}
+
+TEST_F(GCMServiceTest, SendUnderNonPositiveChannelSignal) {
+  // Non-positive channel signal will prevent GCMClient from checking in during
+  // sign-in.
+  wrapper_->CreateService(false, GCMClientMock::NO_DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+
+  // GCMClient should not be checked in.
+  EXPECT_FALSE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::UNINITIALIZED, wrapper_->GetGCMClient()->status());
+
+  // Invoking send will make GCMClient checked in.
+  GCMClient::OutgoingMessage message;
+  message.id = "1";
+  message.data["key1"] = "value1";
+  wrapper_->Send(kTestAppID1, kUserID1, message, TestGCMServiceWrapper::WAIT);
+
+  // GCMClient should be checked in.
+  EXPECT_TRUE(wrapper_->service()->IsGCMClientReady());
+  EXPECT_EQ(GCMClientMock::LOADED, wrapper_->GetGCMClient()->status());
+
+  // Sending should succeed.
+  EXPECT_EQ(message.id, wrapper_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->send_result());
+}
+
+// Tests a single instance of GCMService.
+class GCMServiceSingleInstanceTest : public GCMServiceTest {
+ public:
+  GCMServiceSingleInstanceTest();
+  virtual ~GCMServiceSingleInstanceTest();
+
+  // GCMServiceTest:
+  virtual void SetUp() OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GCMServiceSingleInstanceTest);
+};
+
+GCMServiceSingleInstanceTest::GCMServiceSingleInstanceTest() {
+}
+
+GCMServiceSingleInstanceTest::~GCMServiceSingleInstanceTest() {
+}
+
+void GCMServiceSingleInstanceTest::SetUp() {
+  GCMServiceTest::SetUp();
+
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+}
+
+TEST_F(GCMServiceSingleInstanceTest, Register) {
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+  const std::string expected_registration_id =
+      GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids);
+
+  EXPECT_EQ(expected_registration_id, wrapper_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, RegisterError) {
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1@error");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_TRUE(wrapper_->registration_id().empty());
+  EXPECT_NE(GCMClient::SUCCESS, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, RegisterAgainWithSameSenderIDs) {
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  sender_ids.push_back("sender2");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+  const std::string expected_registration_id =
+      GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids);
+
+  EXPECT_EQ(expected_registration_id, wrapper_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+
+  // Clears the results the would be set by the Register callback in preparation
+  // to call register 2nd time.
+  wrapper_->ClearRegistrationResult();
+
+  // Calling register 2nd time with the same set of sender IDs but different
+  // ordering will get back the same registration ID.
+  std::vector<std::string> another_sender_ids;
+  another_sender_ids.push_back("sender2");
+  another_sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1,
+                     another_sender_ids,
+                     TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(expected_registration_id, wrapper_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, RegisterAgainWithDifferentSenderIDs) {
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+  const std::string expected_registration_id =
+      GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids);
+
+  EXPECT_EQ(expected_registration_id, wrapper_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+
+  // Make sender IDs different.
+  sender_ids.push_back("sender2");
+  const std::string expected_registration_id2 =
+      GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids);
+
+  // Calling register 2nd time with the different sender IDs will get back a new
+  // registration ID.
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+  EXPECT_EQ(expected_registration_id2, wrapper_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, GCMClientNotReadyBeforeRegistration) {
+  // Make GCMClient not ready initially.
+  wrapper_.reset(new TestGCMServiceWrapper(request_context_));
+  wrapper_->CreateService(true, GCMClientMock::DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+
+  // The registration is on hold until GCMClient is ready.
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1,
+                     sender_ids,
+                     TestGCMServiceWrapper::DO_NOT_WAIT);
+  PumpIOLoop();
+  PumpUILoop();
+  EXPECT_TRUE(wrapper_->registration_id().empty());
+  EXPECT_EQ(GCMClient::UNKNOWN_ERROR, wrapper_->registration_result());
+
+  // Register operation will be invoked after GCMClient becomes ready.
+  wrapper_->GetGCMClient()->PerformDelayedLoading();
+  wrapper_->WaitForAsyncOperation();
+  EXPECT_FALSE(wrapper_->registration_id().empty());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, RegisterAfterSignOut) {
+  // This will trigger check-out.
+  wrapper_->SignOut();
+
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_TRUE(wrapper_->registration_id().empty());
+  EXPECT_EQ(GCMClient::NOT_SIGNED_IN, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, UnregisterExplicitly) {
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_FALSE(wrapper_->registration_id().empty());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+
+  wrapper_->Unregister(kTestAppID1, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->unregistration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, UnregisterWhenAsyncOperationPending) {
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  // First start registration without waiting for it to complete.
+  wrapper_->Register(kTestAppID1,
+                     sender_ids,
+                     TestGCMServiceWrapper::DO_NOT_WAIT);
+
+  // Test that unregistration fails with async operation pending when there is a
+  // registration already in progress.
+  wrapper_->Unregister(kTestAppID1, TestGCMServiceWrapper::WAIT);
+  EXPECT_EQ(GCMClient::ASYNC_OPERATION_PENDING,
+            wrapper_->unregistration_result());
+
+  // Complete the unregistration.
+  PumpIOLoop();
+  PumpUILoop();
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+
+  // Start unregistration without waiting for it to complete. This time no async
+  // operation is pending.
+  wrapper_->Unregister(kTestAppID1, TestGCMServiceWrapper::DO_NOT_WAIT);
+
+  // Test that unregistration fails with async operation pending when there is
+  // an unregistration already in progress.
+  wrapper_->Unregister(kTestAppID1, TestGCMServiceWrapper::WAIT);
+  EXPECT_EQ(GCMClient::ASYNC_OPERATION_PENDING,
+            wrapper_->unregistration_result());
+  wrapper_->ClearUnregistrationResult();
+
+  // Complete unregistration.
+  PumpIOLoop();
+  PumpUILoop();
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->unregistration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, RegisterWhenAsyncOperationPending) {
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  // First start registration without waiting for it to complete.
+  wrapper_->Register(kTestAppID1,
+                     sender_ids,
+                     TestGCMServiceWrapper::DO_NOT_WAIT);
+
+  // Test that registration fails with async operation pending when there is a
+  // registration already in progress.
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+  EXPECT_EQ(GCMClient::ASYNC_OPERATION_PENDING,
+            wrapper_->registration_result());
+  wrapper_->ClearRegistrationResult();
+
+  // Complete the registration.
+  PumpIOLoop();
+  PumpUILoop();
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+
+  // Start unregistration without waiting for it to complete. This time no async
+  // operation is pending.
+  wrapper_->Unregister(kTestAppID1, TestGCMServiceWrapper::DO_NOT_WAIT);
+
+  // Test that registration fails with async operation pending when there is an
+  // unregistration already in progress.
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+  EXPECT_EQ(GCMClient::ASYNC_OPERATION_PENDING,
+            wrapper_->registration_result());
+
+  // Complete the first unregistration expecting success.
+  PumpIOLoop();
+  PumpUILoop();
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->unregistration_result());
+
+  // Test that it is ok to register again after unregistration.
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, Send) {
+  GCMClient::OutgoingMessage message;
+  message.id = "1";
+  message.data["key1"] = "value1";
+  message.data["key2"] = "value2";
+  wrapper_->Send(kTestAppID1, kUserID1, message, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(message.id, wrapper_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->send_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, GCMClientNotReadyBeforeSending) {
+  // Make GCMClient not ready initially.
+  wrapper_.reset(new TestGCMServiceWrapper(request_context_));
+  wrapper_->CreateService(true, GCMClientMock::DELAY_LOADING);
+  wrapper_->SignIn(kTestAccountID1);
+
+  // The sending is on hold until GCMClient is ready.
+  GCMClient::OutgoingMessage message;
+  message.id = "1";
+  message.data["key1"] = "value1";
+  message.data["key2"] = "value2";
+  wrapper_->Send(kTestAppID1,
+                 kUserID1,
+                 message,
+                 TestGCMServiceWrapper::DO_NOT_WAIT);
+  PumpIOLoop();
+  PumpUILoop();
+
+  EXPECT_TRUE(wrapper_->send_message_id().empty());
+  EXPECT_EQ(GCMClient::UNKNOWN_ERROR, wrapper_->send_result());
+
+  // Send operation will be invoked after GCMClient becomes ready.
+  wrapper_->GetGCMClient()->PerformDelayedLoading();
+  wrapper_->WaitForAsyncOperation();
+  EXPECT_EQ(message.id, wrapper_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->send_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, SendAfterSignOut) {
+  // This will trigger check-out.
+  wrapper_->SignOut();
+
+  GCMClient::OutgoingMessage message;
+  message.id = "1";
+  message.data["key1"] = "value1";
+  message.data["key2"] = "value2";
+  wrapper_->Send(kTestAppID1, kUserID1, message, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_TRUE(wrapper_->send_message_id().empty());
+  EXPECT_EQ(GCMClient::NOT_SIGNED_IN, wrapper_->send_result());
+}
+
+TEST_F(GCMServiceSingleInstanceTest, SendError) {
+  GCMClient::OutgoingMessage message;
+  // Embedding error in id will tell the mock to simulate the send error.
+  message.id = "1@error";
+  message.data["key1"] = "value1";
+  message.data["key2"] = "value2";
+  wrapper_->Send(kTestAppID1, kUserID1, message, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(message.id, wrapper_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->send_result());
+
+  // Wait for the send error.
+  wrapper_->gcm_app_handler()->WaitForNotification();
+  EXPECT_EQ(FakeGCMAppHandler::SEND_ERROR_EVENT,
+            wrapper_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper_->gcm_app_handler()->app_id());
+  EXPECT_EQ(message.id,
+            wrapper_->gcm_app_handler()->send_error_details().message_id);
+  EXPECT_NE(GCMClient::SUCCESS,
+            wrapper_->gcm_app_handler()->send_error_details().result);
+  EXPECT_EQ(message.data,
+            wrapper_->gcm_app_handler()->send_error_details().additional_data);
+}
+
+TEST_F(GCMServiceSingleInstanceTest, MessageReceived) {
+  wrapper_->Register(kTestAppID1,
+                     ToSenderList("sender"),
+                     TestGCMServiceWrapper::WAIT);
+  GCMClient::IncomingMessage message;
+  message.data["key1"] = "value1";
+  message.data["key2"] = "value2";
+  message.sender_id = "sender";
+  wrapper_->GetGCMClient()->ReceiveMessage(kTestAppID1, message);
+  wrapper_->gcm_app_handler()->WaitForNotification();
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper_->gcm_app_handler()->app_id());
+  EXPECT_EQ(message.data, wrapper_->gcm_app_handler()->message().data);
+  EXPECT_TRUE(wrapper_->gcm_app_handler()->message().collapse_key.empty());
+  EXPECT_EQ(message.sender_id,
+            wrapper_->gcm_app_handler()->message().sender_id);
+}
+
+TEST_F(GCMServiceSingleInstanceTest, MessageWithCollapseKeyReceived) {
+  wrapper_->Register(kTestAppID1,
+                     ToSenderList("sender"),
+                     TestGCMServiceWrapper::WAIT);
+  GCMClient::IncomingMessage message;
+  message.data["key1"] = "value1";
+  message.collapse_key = "collapse_key_value";
+  message.sender_id = "sender";
+  wrapper_->GetGCMClient()->ReceiveMessage(kTestAppID1, message);
+  wrapper_->gcm_app_handler()->WaitForNotification();
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper_->gcm_app_handler()->app_id());
+  EXPECT_EQ(message.data, wrapper_->gcm_app_handler()->message().data);
+  EXPECT_EQ(message.collapse_key,
+            wrapper_->gcm_app_handler()->message().collapse_key);
+}
+
+TEST_F(GCMServiceSingleInstanceTest, MessagesDeleted) {
+  wrapper_->GetGCMClient()->DeleteMessages(kTestAppID1);
+  wrapper_->gcm_app_handler()->WaitForNotification();
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGES_DELETED_EVENT,
+            wrapper_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper_->gcm_app_handler()->app_id());
+}
+
+// Tests to make sure that concurrent GCMService instances work correctly
+// regardless how GCMClient is created.
+class GCMServiceMultipleInstanceTest : public GCMServiceTest {
+ protected:
+  GCMServiceMultipleInstanceTest();
+  virtual ~GCMServiceMultipleInstanceTest();
+
+  // GCMServiceTest:
+  virtual void SetUp() OVERRIDE;
+  virtual void TearDown() OVERRIDE;
+
+  scoped_ptr<TestGCMServiceWrapper> wrapper2_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GCMServiceMultipleInstanceTest);
+};
+
+GCMServiceMultipleInstanceTest::GCMServiceMultipleInstanceTest() {
+}
+
+GCMServiceMultipleInstanceTest::~GCMServiceMultipleInstanceTest() {
+}
+
+void GCMServiceMultipleInstanceTest::SetUp() {
+  GCMServiceTest::SetUp();
+
+  wrapper2_.reset(new TestGCMServiceWrapper(request_context_));
+
+  wrapper_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+  wrapper2_->CreateService(true, GCMClientMock::NO_DELAY_LOADING);
+
+  // Initiate check-in for each instance.
+  wrapper_->SignIn(kTestAccountID1);
+  wrapper2_->SignIn(kTestAccountID2);
+}
+
+void GCMServiceMultipleInstanceTest::TearDown() {
+  wrapper2_.reset();
+}
+
+TEST_F(GCMServiceMultipleInstanceTest, Register) {
+  // Register an app.
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+
+  // Register the same app in a different instance.
+  std::vector<std::string> sender_ids2;
+  sender_ids2.push_back("foo");
+  sender_ids2.push_back("bar");
+  wrapper2_->Register(kTestAppID1, sender_ids2, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids),
+            wrapper_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+
+  EXPECT_EQ(GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids2),
+            wrapper2_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper2_->registration_result());
+
+  // Register a different app in a different instance.
+  std::vector<std::string> sender_ids3;
+  sender_ids3.push_back("sender1");
+  sender_ids3.push_back("sender2");
+  sender_ids3.push_back("sender3");
+  wrapper2_->Register(kTestAppID2, sender_ids3, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids3),
+            wrapper2_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper2_->registration_result());
+}
+
+TEST_F(GCMServiceMultipleInstanceTest, Send) {
+  // Send a message from one app in one instance.
+  GCMClient::OutgoingMessage message;
+  message.id = "1";
+  message.data["key1"] = "value1";
+  message.data["key2"] = "value2";
+  wrapper_->Send(kTestAppID1, kUserID1, message, TestGCMServiceWrapper::WAIT);
+
+  // Send a message from same app in another instance.
+  GCMClient::OutgoingMessage message2;
+  message2.id = "2";
+  message2.data["foo"] = "bar";
+  wrapper2_->Send(kTestAppID1, kUserID2, message2, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(message.id, wrapper_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->send_result());
+
+  EXPECT_EQ(message2.id, wrapper2_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper2_->send_result());
+
+  // Send another message from different app in another instance.
+  GCMClient::OutgoingMessage message3;
+  message3.id = "3";
+  message3.data["hello"] = "world";
+  wrapper2_->Send(kTestAppID2, kUserID1, message3, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(message3.id, wrapper2_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper2_->send_result());
+}
+
+TEST_F(GCMServiceMultipleInstanceTest, MessageReceived) {
+  wrapper_->Register(kTestAppID1,
+                     ToSenderList("sender"),
+                     TestGCMServiceWrapper::WAIT);
+  wrapper2_->Register(kTestAppID1,
+                      ToSenderList("sender"),
+                      TestGCMServiceWrapper::WAIT);
+  wrapper2_->Register(kTestAppID2,
+                      ToSenderList("sender2"),
+                      TestGCMServiceWrapper::WAIT);
+
+  // Trigger an incoming message for an app in one instance.
+  GCMClient::IncomingMessage message;
+  message.data["key1"] = "value1";
+  message.data["key2"] = "value2";
+  message.sender_id = "sender";
+  wrapper_->GetGCMClient()->ReceiveMessage(kTestAppID1, message);
+  wrapper_->gcm_app_handler()->WaitForNotification();
+
+  // Trigger an incoming message for the same app in another instance.
+  GCMClient::IncomingMessage message2;
+  message2.data["foo"] = "bar";
+  message2.sender_id = "sender";
+  wrapper2_->GetGCMClient()->ReceiveMessage(kTestAppID1, message2);
+  wrapper2_->gcm_app_handler()->WaitForNotification();
+
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper_->gcm_app_handler()->app_id());
+  EXPECT_EQ(message.data, wrapper_->gcm_app_handler()->message().data);
+  EXPECT_EQ("sender", wrapper_->gcm_app_handler()->message().sender_id);
+
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper2_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper2_->gcm_app_handler()->app_id());
+  EXPECT_EQ(message2.data, wrapper2_->gcm_app_handler()->message().data);
+  EXPECT_EQ("sender", wrapper2_->gcm_app_handler()->message().sender_id);
+
+  // Trigger another incoming message for a different app in another instance.
+  GCMClient::IncomingMessage message3;
+  message3.data["bar1"] = "foo1";
+  message3.data["bar2"] = "foo2";
+  message3.sender_id = "sender2";
+  wrapper2_->GetGCMClient()->ReceiveMessage(kTestAppID2, message3);
+  wrapper2_->gcm_app_handler()->WaitForNotification();
+
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper2_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID2, wrapper2_->gcm_app_handler()->app_id());
+  EXPECT_EQ(message3.data, wrapper2_->gcm_app_handler()->message().data);
+  EXPECT_EQ("sender2", wrapper2_->gcm_app_handler()->message().sender_id);
+}
+
+// Test a set of GCM operations on multiple instances.
+// 1) Register 1 app in instance 1 and register 2 apps in instance 2;
+// 2) Send a message from instance 1;
+// 3) Receive a message to an app in instance 1 and receive a message for each
+//    of the two apps in instance 2;
+// 4) Send a message for each of the two apps in instance 2;
+// 5) Sign out of instance 1.
+// 6) Register/send stops working for instance 1;
+// 7) The app in instance 2 can still receive these events;
+// 8) Sign into instance 1 with a different account.
+// 9) The message to the newly signed-in account will be routed.
+TEST_F(GCMServiceMultipleInstanceTest, Combined) {
+  // Register an app.
+  std::vector<std::string> sender_ids;
+  sender_ids.push_back("sender1");
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+
+  // Register the same app in a different instance.
+  std::vector<std::string> sender_ids2;
+  sender_ids2.push_back("foo");
+  sender_ids2.push_back("bar");
+  wrapper2_->Register(kTestAppID1, sender_ids2, TestGCMServiceWrapper::WAIT);
+
+  // Register a different app in a different instance.
+  std::vector<std::string> sender_ids3;
+  sender_ids3.push_back("sender1");
+  sender_ids3.push_back("sender2");
+  sender_ids3.push_back("sender3");
+  wrapper2_->Register(kTestAppID2, sender_ids3, TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids),
+            wrapper_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->registration_result());
+
+  EXPECT_EQ(GCMClientMock::GetRegistrationIdFromSenderIds(sender_ids3),
+            wrapper2_->registration_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper2_->registration_result());
+
+  // Send a message from one instance.
+  GCMClient::OutgoingMessage out_message;
+  out_message.id = "1";
+  out_message.data["out1"] = "out_data1";
+  out_message.data["out1_2"] = "out_data1_2";
+  wrapper_->Send(kTestAppID1,
+                 kUserID1,
+                 out_message,
+                 TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(out_message.id, wrapper_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper_->send_result());
+
+  // Trigger an incoming message for an app in one instance.
+  GCMClient::IncomingMessage in_message;
+  in_message.data["in1"] = "in_data1";
+  in_message.data["in1_2"] = "in_data1_2";
+  in_message.sender_id = "sender1";
+  wrapper_->GetGCMClient()->ReceiveMessage(kTestAppID1, in_message);
+  wrapper_->gcm_app_handler()->WaitForNotification();
+
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper_->gcm_app_handler()->app_id());
+  EXPECT_EQ(in_message.data, wrapper_->gcm_app_handler()->message().data);
+
+  // Trigger 2 incoming messages, one for each app respectively, in another
+  // instance.
+  GCMClient::IncomingMessage in_message2;
+  in_message2.data["in2"] = "in_data2";
+  in_message2.sender_id = "sender3";
+  wrapper2_->GetGCMClient()->ReceiveMessage(kTestAppID2, in_message2);
+
+  GCMClient::IncomingMessage in_message3;
+  in_message3.data["in3"] = "in_data3";
+  in_message3.data["in3_2"] = "in_data3_2";
+  in_message3.sender_id = "foo";
+  wrapper2_->GetGCMClient()->ReceiveMessage(kTestAppID1, in_message3);
+
+  wrapper2_->gcm_app_handler()->WaitForNotification();
+
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper2_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID2, wrapper2_->gcm_app_handler()->app_id());
+  EXPECT_EQ(in_message2.data, wrapper2_->gcm_app_handler()->message().data);
+
+  wrapper2_->gcm_app_handler()->WaitForNotification();
+
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper2_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper2_->gcm_app_handler()->app_id());
+  EXPECT_EQ(in_message3.data, wrapper2_->gcm_app_handler()->message().data);
+
+  // Send two messages, one for each app respectively, from another instance.
+  GCMClient::OutgoingMessage out_message2;
+  out_message2.id = "2";
+  out_message2.data["out2"] = "out_data2";
+  wrapper2_->Send(kTestAppID1,
+                  kUserID2,
+                  out_message2,
+                  TestGCMServiceWrapper::WAIT);
+
+  GCMClient::OutgoingMessage out_message3;
+  out_message3.id = "3";
+  out_message3.data["out3"] = "out_data3";
+  wrapper2_->Send(kTestAppID2,
+                  kUserID2,
+                  out_message3,
+                  TestGCMServiceWrapper::DO_NOT_WAIT);
+
+  EXPECT_EQ(out_message2.id, wrapper2_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper2_->send_result());
+
+  PumpIOLoop();
+  PumpUILoop();
+
+  EXPECT_EQ(out_message3.id, wrapper2_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper2_->send_result());
+
+  // Sign out of one instance.
+  wrapper_->SignOut();
+
+  // Register/send stops working for signed-out instance.
+  wrapper_->Register(kTestAppID1, sender_ids, TestGCMServiceWrapper::WAIT);
+  EXPECT_TRUE(wrapper_->registration_id().empty());
+  EXPECT_EQ(GCMClient::NOT_SIGNED_IN, wrapper_->registration_result());
+
+  wrapper_->Send(kTestAppID2,
+                 kUserID2,
+                 out_message3,
+                 TestGCMServiceWrapper::WAIT);
+  EXPECT_TRUE(wrapper_->send_message_id().empty());
+  EXPECT_EQ(GCMClient::NOT_SIGNED_IN, wrapper_->send_result());
+
+  // Deleted messages event will go through for another signed-in instance.
+  wrapper2_->GetGCMClient()->DeleteMessages(kTestAppID2);
+  wrapper2_->gcm_app_handler()->WaitForNotification();
+
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGES_DELETED_EVENT,
+            wrapper2_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID2, wrapper2_->gcm_app_handler()->app_id());
+
+  // Send error event will go through for another signed-in instance.
+  GCMClient::OutgoingMessage out_message4;
+  out_message4.id = "1@error";
+  out_message4.data["out4"] = "out_data4";
+  wrapper2_->Send(kTestAppID1,
+                  kUserID1,
+                  out_message4,
+                  TestGCMServiceWrapper::WAIT);
+
+  EXPECT_EQ(out_message4.id, wrapper2_->send_message_id());
+  EXPECT_EQ(GCMClient::SUCCESS, wrapper2_->send_result());
+
+  wrapper2_->gcm_app_handler()->WaitForNotification();
+  EXPECT_EQ(FakeGCMAppHandler::SEND_ERROR_EVENT,
+            wrapper2_->gcm_app_handler()->received_event());
+  EXPECT_EQ(kTestAppID1, wrapper2_->gcm_app_handler()->app_id());
+  EXPECT_EQ(out_message4.id,
+            wrapper2_->gcm_app_handler()->send_error_details().message_id);
+  EXPECT_NE(GCMClient::SUCCESS,
+            wrapper2_->gcm_app_handler()->send_error_details().result);
+  EXPECT_EQ(out_message4.data,
+            wrapper2_->gcm_app_handler()->send_error_details().additional_data);
+
+  // Sign in with a different account.
+  wrapper_->SignIn(kTestAccountID3);
+
+  // Signing out cleared all registrations, so we need to register again.
+  wrapper_->Register(kTestAppID1,
+                     ToSenderList("sender1"),
+                     TestGCMServiceWrapper::WAIT);
+
+  // Incoming message will go through for the new signed-in account.
+  GCMClient::IncomingMessage in_message5;
+  in_message5.data["in5"] = "in_data5";
+  in_message5.sender_id = "sender1";
+  wrapper_->GetGCMClient()->ReceiveMessage(kTestAppID1, in_message5);
+
+  wrapper_->gcm_app_handler()->WaitForNotification();
+
+  EXPECT_EQ(FakeGCMAppHandler::MESSAGE_EVENT,
+            wrapper_->gcm_app_handler()->received_event());
+  EXPECT_EQ(in_message5.data, wrapper_->gcm_app_handler()->message().data);
+}
+
+}  // namespace gcm