src/google_apis/gcm/engine/connection_factory_impl_unittest.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "google_apis/gcm/engine/connection_factory_impl.h"
   6
   7 #include <cmath>
   8
   9 #include "base/message_loop/message_loop.h"
  10 #include "base/run_loop.h"
  11 #include "base/test/simple_test_tick_clock.h"
  12 #include "google_apis/gcm/base/mcs_util.h"
  13 #include "google_apis/gcm/engine/fake_connection_handler.h"
  14 #include "google_apis/gcm/monitoring/fake_gcm_stats_recorder.h"
  15 #include "net/base/backoff_entry.h"
  16 #include "net/http/http_network_session.h"
  17 #include "testing/gtest/include/gtest/gtest.h"
  18
  19 class Policy;
  20
  21 namespace gcm {
  22 namespace {
  23
  24 const char kMCSEndpoint[] = "http://my.server";
  25 const char kMCSEndpoint2[] = "http://my.alt.server";
  26
  27 const int kBackoffDelayMs = 1;
  28 const int kBackoffMultiplier = 2;
  29
  30 // A backoff policy with small enough delays that tests aren't burdened.
  31 const net::BackoffEntry::Policy kTestBackoffPolicy = {
  32   // Number of initial errors (in sequence) to ignore before applying
  33   // exponential back-off rules.
  34   0,
  35
  36   // Initial delay for exponential back-off in ms.
  37   kBackoffDelayMs,
  38
  39   // Factor by which the waiting time will be multiplied.
  40   kBackoffMultiplier,
  41
  42   // Fuzzing percentage. ex: 10% will spread requests randomly
  43   // between 90%-100% of the calculated time.
  44   0,
  45
  46   // Maximum amount of time we are willing to delay our request in ms.
  47   10,
  48
  49   // Time to keep an entry from being discarded even when it
  50   // has no significant state, -1 to never discard.
  51   -1,
  52
  53   // Don't use initial delay unless the last request was an error.
  54   false,
  55 };
  56
  57 std::vector<GURL> BuildEndpoints() {
  58   std::vector<GURL> endpoints;
  59   endpoints.push_back(GURL(kMCSEndpoint));
  60   endpoints.push_back(GURL(kMCSEndpoint2));
  61   return endpoints;
  62 }
  63
  64 // Helper for calculating total expected exponential backoff delay given an
  65 // arbitrary number of failed attempts. See BackoffEntry::CalculateReleaseTime.
  66 double CalculateBackoff(int num_attempts) {
  67   double delay = kBackoffDelayMs;
  68   for (int i = 1; i < num_attempts; ++i) {
  69     delay += kBackoffDelayMs * pow(static_cast<double>(kBackoffMultiplier),
  70                                    i - 1);
  71   }
  72   DVLOG(1) << "Expected backoff " << delay << " milliseconds.";
  73   return delay;
  74 }
  75
  76 void ReadContinuation(
  77     scoped_ptr<google::protobuf::MessageLite> message) {
  78 }
  79
  80 void WriteContinuation() {
  81 }
  82
  83 class TestBackoffEntry : public net::BackoffEntry {
  84  public:
  85   explicit TestBackoffEntry(base::SimpleTestTickClock* tick_clock);
  86   ~TestBackoffEntry() override;
  87
  88   base::TimeTicks ImplGetTimeNow() const override;
  89
  90  private:
  91   base::SimpleTestTickClock* tick_clock_;
  92 };
  93
  94 TestBackoffEntry::TestBackoffEntry(base::SimpleTestTickClock* tick_clock)
  95     : BackoffEntry(&kTestBackoffPolicy),
  96       tick_clock_(tick_clock) {
  97 }
  98
  99 TestBackoffEntry::~TestBackoffEntry() {}
 100
 101 base::TimeTicks TestBackoffEntry::ImplGetTimeNow() const {
 102   return tick_clock_->NowTicks();
 103 }
 104
 105 // A connection factory that stubs out network requests and overrides the
 106 // backoff policy.
 107 class TestConnectionFactoryImpl : public ConnectionFactoryImpl {
 108  public:
 109   TestConnectionFactoryImpl(const base::Closure& finished_callback);
 110   ~TestConnectionFactoryImpl() override;
 111
 112   void InitializeFactory();
 113
 114   // Overridden stubs.
 115   void ConnectImpl() override;
 116   void InitHandler() override;
 117   scoped_ptr<net::BackoffEntry> CreateBackoffEntry(
 118       const net::BackoffEntry::Policy* const policy) override;
 119   scoped_ptr<ConnectionHandler> CreateConnectionHandler(
 120       base::TimeDelta read_timeout,
 121       const ConnectionHandler::ProtoReceivedCallback& read_callback,
 122       const ConnectionHandler::ProtoSentCallback& write_callback,
 123       const ConnectionHandler::ConnectionChangedCallback& connection_callback)
 124       override;
 125   base::TimeTicks NowTicks() override;
 126
 127   // Helpers for verifying connection attempts are made. Connection results
 128   // must be consumed.
 129   void SetConnectResult(int connect_result);
 130   void SetMultipleConnectResults(int connect_result, int num_expected_attempts);
 131
 132   // Force a login handshake to be delayed.
 133   void SetDelayLogin(bool delay_login);
 134
 135   base::SimpleTestTickClock* tick_clock() { return &tick_clock_; }
 136
 137  private:
 138   // Clock for controlling delay.
 139   base::SimpleTestTickClock tick_clock_;
 140   // The result to return on the next connect attempt.
 141   int connect_result_;
 142   // The number of expected connection attempts;
 143   int num_expected_attempts_;
 144   // Whether all expected connection attempts have been fulfilled since an
 145   // expectation was last set.
 146   bool connections_fulfilled_;
 147   // Whether to delay a login handshake completion or not.
 148   bool delay_login_;
 149   // Callback to invoke when all connection attempts have been made.
 150   base::Closure finished_callback_;
 151   // The current fake connection handler..
 152   FakeConnectionHandler* fake_handler_;
 153   FakeGCMStatsRecorder dummy_recorder_;
 154 };
 155
 156 TestConnectionFactoryImpl::TestConnectionFactoryImpl(
 157     const base::Closure& finished_callback)
 158     : ConnectionFactoryImpl(BuildEndpoints(),
 159                             net::BackoffEntry::Policy(),
 160                             NULL,
 161                             NULL,
 162                             NULL,
 163                             &dummy_recorder_),
 164       connect_result_(net::ERR_UNEXPECTED),
 165       num_expected_attempts_(0),
 166       connections_fulfilled_(true),
 167       delay_login_(false),
 168       finished_callback_(finished_callback),
 169       fake_handler_(NULL) {
 170   // Set a non-null time.
 171   tick_clock_.Advance(base::TimeDelta::FromMilliseconds(1));
 172 }
 173
 174 TestConnectionFactoryImpl::~TestConnectionFactoryImpl() {
 175   EXPECT_EQ(0, num_expected_attempts_);
 176 }
 177
 178 void TestConnectionFactoryImpl::ConnectImpl() {
 179   ASSERT_GT(num_expected_attempts_, 0);
 180   scoped_ptr<mcs_proto::LoginRequest> request(BuildLoginRequest(0, 0, ""));
 181   GetConnectionHandler()->Init(*request, NULL);
 182   OnConnectDone(connect_result_);
 183   if (!NextRetryAttempt().is_null()) {
 184     // Advance the time to the next retry time.
 185     base::TimeDelta time_till_retry =
 186         NextRetryAttempt() - tick_clock_.NowTicks();
 187     tick_clock_.Advance(time_till_retry);
 188   }
 189   --num_expected_attempts_;
 190   if (num_expected_attempts_ == 0) {
 191     connect_result_ = net::ERR_UNEXPECTED;
 192     connections_fulfilled_ = true;
 193     finished_callback_.Run();
 194   }
 195 }
 196
 197 void TestConnectionFactoryImpl::InitHandler() {
 198   EXPECT_NE(connect_result_, net::ERR_UNEXPECTED);
 199   if (!delay_login_)
 200     ConnectionHandlerCallback(net::OK);
 201 }
 202
 203 scoped_ptr<net::BackoffEntry> TestConnectionFactoryImpl::CreateBackoffEntry(
 204     const net::BackoffEntry::Policy* const policy) {
 205   return scoped_ptr<net::BackoffEntry>(new TestBackoffEntry(&tick_clock_));
 206 }
 207
 208 scoped_ptr<ConnectionHandler>
 209 TestConnectionFactoryImpl::CreateConnectionHandler(
 210     base::TimeDelta read_timeout,
 211     const ConnectionHandler::ProtoReceivedCallback& read_callback,
 212     const ConnectionHandler::ProtoSentCallback& write_callback,
 213     const ConnectionHandler::ConnectionChangedCallback& connection_callback) {
 214   fake_handler_ = new FakeConnectionHandler(
 215       base::Bind(&ReadContinuation),
 216       base::Bind(&WriteContinuation));
 217   return make_scoped_ptr<ConnectionHandler>(fake_handler_);
 218 }
 219
 220 base::TimeTicks TestConnectionFactoryImpl::NowTicks() {
 221   return tick_clock_.NowTicks();
 222 }
 223
 224 void TestConnectionFactoryImpl::SetConnectResult(int connect_result) {
 225   DCHECK_NE(connect_result, net::ERR_UNEXPECTED);
 226   ASSERT_EQ(0, num_expected_attempts_);
 227   connections_fulfilled_ = false;
 228   connect_result_ = connect_result;
 229   num_expected_attempts_ = 1;
 230   fake_handler_->ExpectOutgoingMessage(
 231       MCSMessage(kLoginRequestTag, BuildLoginRequest(0, 0, "")));
 232 }
 233
 234 void TestConnectionFactoryImpl::SetMultipleConnectResults(
 235     int connect_result,
 236     int num_expected_attempts) {
 237   DCHECK_NE(connect_result, net::ERR_UNEXPECTED);
 238   DCHECK_GT(num_expected_attempts, 0);
 239   ASSERT_EQ(0, num_expected_attempts_);
 240   connections_fulfilled_ = false;
 241   connect_result_ = connect_result;
 242   num_expected_attempts_ = num_expected_attempts;
 243   for (int i = 0 ; i < num_expected_attempts; ++i) {
 244     fake_handler_->ExpectOutgoingMessage(
 245         MCSMessage(kLoginRequestTag, BuildLoginRequest(0, 0, "")));
 246   }
 247 }
 248
 249 void TestConnectionFactoryImpl::SetDelayLogin(bool delay_login) {
 250   delay_login_ = delay_login;
 251   fake_handler_->set_fail_login(delay_login_);
 252 }
 253
 254 }  // namespace
 255
 256 class ConnectionFactoryImplTest
 257     : public testing::Test,
 258       public ConnectionFactory::ConnectionListener {
 259  public:
 260   ConnectionFactoryImplTest();
 261   virtual ~ConnectionFactoryImplTest();
 262
 263   TestConnectionFactoryImpl* factory() { return &factory_; }
 264   GURL& connected_server() { return connected_server_; }
 265
 266   void WaitForConnections();
 267
 268   // ConnectionFactory::ConnectionListener
 269   void OnConnected(const GURL& current_server,
 270                    const net::IPEndPoint& ip_endpoint) override;
 271   void OnDisconnected() override;
 272
 273  private:
 274   void ConnectionsComplete();
 275
 276   TestConnectionFactoryImpl factory_;
 277   base::MessageLoop message_loop_;
 278   scoped_ptr<base::RunLoop> run_loop_;
 279
 280   GURL connected_server_;
 281 };
 282
 283 ConnectionFactoryImplTest::ConnectionFactoryImplTest()
 284    : factory_(base::Bind(&ConnectionFactoryImplTest::ConnectionsComplete,
 285                          base::Unretained(this))),
 286      run_loop_(new base::RunLoop()) {
 287   factory()->SetConnectionListener(this);
 288   factory()->Initialize(
 289       ConnectionFactory::BuildLoginRequestCallback(),
 290       ConnectionHandler::ProtoReceivedCallback(),
 291       ConnectionHandler::ProtoSentCallback());
 292 }
 293 ConnectionFactoryImplTest::~ConnectionFactoryImplTest() {}
 294
 295 void ConnectionFactoryImplTest::WaitForConnections() {
 296   run_loop_->Run();
 297   run_loop_.reset(new base::RunLoop());
 298 }
 299
 300 void ConnectionFactoryImplTest::ConnectionsComplete() {
 301   if (!run_loop_)
 302     return;
 303   run_loop_->Quit();
 304 }
 305
 306 void ConnectionFactoryImplTest::OnConnected(
 307     const GURL& current_server,
 308     const net::IPEndPoint& ip_endpoint) {
 309   connected_server_ = current_server;
 310 }
 311
 312 void ConnectionFactoryImplTest::OnDisconnected() {
 313   connected_server_ = GURL();
 314 }
 315
 316 // Verify building a connection handler works.
 317 TEST_F(ConnectionFactoryImplTest, Initialize) {
 318   ConnectionHandler* handler = factory()->GetConnectionHandler();
 319   ASSERT_TRUE(handler);
 320   EXPECT_FALSE(factory()->IsEndpointReachable());
 321   EXPECT_FALSE(connected_server().is_valid());
 322 }
 323
 324 // An initial successful connection should not result in backoff.
 325 TEST_F(ConnectionFactoryImplTest, ConnectSuccess) {
 326   factory()->SetConnectResult(net::OK);
 327   factory()->Connect();
 328   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 329   EXPECT_EQ(factory()->GetCurrentEndpoint(), BuildEndpoints()[0]);
 330   EXPECT_TRUE(factory()->IsEndpointReachable());
 331   EXPECT_TRUE(connected_server().is_valid());
 332 }
 333
 334 // A connection failure should result in backoff, and attempting the fallback
 335 // endpoint next.
 336 TEST_F(ConnectionFactoryImplTest, ConnectFail) {
 337   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 338   factory()->Connect();
 339   EXPECT_FALSE(factory()->NextRetryAttempt().is_null());
 340   EXPECT_EQ(factory()->GetCurrentEndpoint(), BuildEndpoints()[1]);
 341   EXPECT_FALSE(factory()->IsEndpointReachable());
 342   EXPECT_FALSE(connected_server().is_valid());
 343 }
 344
 345 // A connection success after a failure should reset backoff.
 346 TEST_F(ConnectionFactoryImplTest, FailThenSucceed) {
 347   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 348   base::TimeTicks connect_time = factory()->tick_clock()->NowTicks();
 349   factory()->Connect();
 350   WaitForConnections();
 351   EXPECT_FALSE(factory()->IsEndpointReachable());
 352   EXPECT_FALSE(connected_server().is_valid());
 353   base::TimeTicks retry_time = factory()->NextRetryAttempt();
 354   EXPECT_FALSE(retry_time.is_null());
 355   EXPECT_GE((retry_time - connect_time).InMilliseconds(), CalculateBackoff(1));
 356   factory()->SetConnectResult(net::OK);
 357   WaitForConnections();
 358   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 359   EXPECT_TRUE(factory()->IsEndpointReachable());
 360   EXPECT_TRUE(connected_server().is_valid());
 361 }
 362
 363 // Multiple connection failures should retry with an exponentially increasing
 364 // backoff, then reset on success.
 365 TEST_F(ConnectionFactoryImplTest, MultipleFailuresThenSucceed) {
 366   const int kNumAttempts = 5;
 367   factory()->SetMultipleConnectResults(net::ERR_CONNECTION_FAILED,
 368                                        kNumAttempts);
 369
 370   base::TimeTicks connect_time = factory()->tick_clock()->NowTicks();
 371   factory()->Connect();
 372   WaitForConnections();
 373   EXPECT_FALSE(factory()->IsEndpointReachable());
 374   EXPECT_FALSE(connected_server().is_valid());
 375   base::TimeTicks retry_time = factory()->NextRetryAttempt();
 376   EXPECT_FALSE(retry_time.is_null());
 377   EXPECT_GE((retry_time - connect_time).InMilliseconds(),
 378             CalculateBackoff(kNumAttempts));
 379
 380   factory()->SetConnectResult(net::OK);
 381   WaitForConnections();
 382   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 383   EXPECT_TRUE(factory()->IsEndpointReachable());
 384   EXPECT_TRUE(connected_server().is_valid());
 385 }
 386
 387 // Network change events should trigger canary connections.
 388 TEST_F(ConnectionFactoryImplTest, FailThenNetworkChangeEvent) {
 389   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 390   factory()->Connect();
 391   WaitForConnections();
 392   base::TimeTicks initial_backoff = factory()->NextRetryAttempt();
 393   EXPECT_FALSE(initial_backoff.is_null());
 394
 395   factory()->SetConnectResult(net::ERR_FAILED);
 396   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_WIFI);
 397   WaitForConnections();
 398
 399   // Backoff should increase.
 400   base::TimeTicks next_backoff = factory()->NextRetryAttempt();
 401   EXPECT_GT(next_backoff, initial_backoff);
 402   EXPECT_FALSE(factory()->IsEndpointReachable());
 403 }
 404
 405 // Verify that we reconnect even if a canary succeeded then disconnected while
 406 // a backoff was pending.
 407 TEST_F(ConnectionFactoryImplTest, CanarySucceedsThenDisconnects) {
 408   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 409   factory()->Connect();
 410   WaitForConnections();
 411   base::TimeTicks initial_backoff = factory()->NextRetryAttempt();
 412   EXPECT_FALSE(initial_backoff.is_null());
 413
 414   factory()->SetConnectResult(net::OK);
 415   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_ETHERNET);
 416   WaitForConnections();
 417   EXPECT_TRUE(factory()->IsEndpointReachable());
 418   EXPECT_TRUE(connected_server().is_valid());
 419
 420   factory()->SetConnectResult(net::OK);
 421   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 422   EXPECT_FALSE(factory()->IsEndpointReachable());
 423   EXPECT_FALSE(connected_server().is_valid());
 424   WaitForConnections();
 425   EXPECT_TRUE(factory()->IsEndpointReachable());
 426   EXPECT_TRUE(connected_server().is_valid());
 427 }
 428
 429 // Verify that if a canary connects, but hasn't finished the handshake, a
 430 // pending backoff attempt doesn't interrupt the connection.
 431 TEST_F(ConnectionFactoryImplTest, CanarySucceedsRetryDuringLogin) {
 432   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 433   factory()->Connect();
 434   WaitForConnections();
 435   base::TimeTicks initial_backoff = factory()->NextRetryAttempt();
 436   EXPECT_FALSE(initial_backoff.is_null());
 437
 438   factory()->SetDelayLogin(true);
 439   factory()->SetConnectResult(net::OK);
 440   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_WIFI);
 441   WaitForConnections();
 442   EXPECT_FALSE(factory()->IsEndpointReachable());
 443
 444   // Pump the loop, to ensure the pending backoff retry has no effect.
 445   base::MessageLoop::current()->PostDelayedTask(
 446       FROM_HERE,
 447       base::MessageLoop::QuitClosure(),
 448       base::TimeDelta::FromMilliseconds(1));
 449   WaitForConnections();
 450 }
 451
 452 // Fail after successful connection via signal reset.
 453 TEST_F(ConnectionFactoryImplTest, FailViaSignalReset) {
 454   factory()->SetConnectResult(net::OK);
 455   factory()->Connect();
 456   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 457
 458   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 459   EXPECT_FALSE(factory()->NextRetryAttempt().is_null());
 460   EXPECT_FALSE(factory()->IsEndpointReachable());
 461 }
 462
 463 TEST_F(ConnectionFactoryImplTest, IgnoreResetWhileConnecting) {
 464   factory()->SetConnectResult(net::OK);
 465   factory()->Connect();
 466   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 467
 468   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 469   base::TimeTicks retry_time = factory()->NextRetryAttempt();
 470   EXPECT_FALSE(retry_time.is_null());
 471   EXPECT_FALSE(factory()->IsEndpointReachable());
 472
 473   const int kNumAttempts = 5;
 474   for (int i = 0; i < kNumAttempts; ++i)
 475     factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 476   EXPECT_EQ(retry_time, factory()->NextRetryAttempt());
 477   EXPECT_FALSE(factory()->IsEndpointReachable());
 478 }
 479
 480 // Go into backoff due to connection failure. On successful connection, receive
 481 // a signal reset. The original backoff should be restored and extended, rather
 482 // than a new backoff starting from scratch.
 483 TEST_F(ConnectionFactoryImplTest, SignalResetRestoresBackoff) {
 484   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 485   base::TimeTicks connect_time = factory()->tick_clock()->NowTicks();
 486   factory()->Connect();
 487   WaitForConnections();
 488   base::TimeTicks retry_time = factory()->NextRetryAttempt();
 489   EXPECT_FALSE(retry_time.is_null());
 490
 491   factory()->SetConnectResult(net::OK);
 492   connect_time = factory()->tick_clock()->NowTicks();
 493   WaitForConnections();
 494   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 495
 496   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 497   EXPECT_FALSE(factory()->IsEndpointReachable());
 498   EXPECT_FALSE(connected_server().is_valid());
 499   EXPECT_NE(retry_time, factory()->NextRetryAttempt());
 500   retry_time = factory()->NextRetryAttempt();
 501   EXPECT_FALSE(retry_time.is_null());
 502   EXPECT_GE((retry_time - connect_time).InMilliseconds(),
 503             CalculateBackoff(2));
 504
 505   factory()->SetConnectResult(net::OK);
 506   connect_time = factory()->tick_clock()->NowTicks();
 507   factory()->tick_clock()->Advance(
 508       factory()->NextRetryAttempt() - connect_time);
 509   WaitForConnections();
 510   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 511   EXPECT_TRUE(factory()->IsEndpointReachable());
 512   EXPECT_TRUE(connected_server().is_valid());
 513
 514   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 515   EXPECT_NE(retry_time, factory()->NextRetryAttempt());
 516   retry_time = factory()->NextRetryAttempt();
 517   EXPECT_FALSE(retry_time.is_null());
 518   EXPECT_GE((retry_time - connect_time).InMilliseconds(),
 519             CalculateBackoff(3));
 520   EXPECT_FALSE(factory()->IsEndpointReachable());
 521   EXPECT_FALSE(connected_server().is_valid());
 522 }
 523
 524 // When the network is disconnected, close the socket and suppress further
 525 // connection attempts until the network returns.
 526 // Disabled while crbug.com/396687 is being investigated.
 527 TEST_F(ConnectionFactoryImplTest, DISABLED_SuppressConnectWhenNoNetwork) {
 528   factory()->SetConnectResult(net::OK);
 529   factory()->Connect();
 530   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 531   EXPECT_TRUE(factory()->IsEndpointReachable());
 532
 533   // Advance clock so the login window reset isn't encountered.
 534   factory()->tick_clock()->Advance(base::TimeDelta::FromSeconds(11));
 535
 536   // Will trigger reset, but will not attempt a new connection.
 537   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_NONE);
 538   EXPECT_FALSE(factory()->IsEndpointReachable());
 539   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 540
 541   // When the network returns, attempt to connect.
 542   factory()->SetConnectResult(net::OK);
 543   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_4G);
 544   WaitForConnections();
 545
 546   EXPECT_TRUE(factory()->IsEndpointReachable());
 547   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 548 }
 549
 550 }  // namespace gcm