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   virtual ~TestBackoffEntry();
  87
  88   virtual 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   virtual ~TestConnectionFactoryImpl();
 111
 112   void InitializeFactory();
 113
 114   // Overridden stubs.
 115   virtual void ConnectImpl() OVERRIDE;
 116   virtual void InitHandler() OVERRIDE;
 117   virtual scoped_ptr<net::BackoffEntry> CreateBackoffEntry(
 118       const net::BackoffEntry::Policy* const policy) OVERRIDE;
 119   virtual 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   virtual 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                             &dummy_recorder_),
 163       connect_result_(net::ERR_UNEXPECTED),
 164       num_expected_attempts_(0),
 165       connections_fulfilled_(true),
 166       delay_login_(false),
 167       finished_callback_(finished_callback),
 168       fake_handler_(NULL) {
 169   // Set a non-null time.
 170   tick_clock_.Advance(base::TimeDelta::FromMilliseconds(1));
 171 }
 172
 173 TestConnectionFactoryImpl::~TestConnectionFactoryImpl() {
 174   EXPECT_EQ(0, num_expected_attempts_);
 175 }
 176
 177 void TestConnectionFactoryImpl::ConnectImpl() {
 178   ASSERT_GT(num_expected_attempts_, 0);
 179   scoped_ptr<mcs_proto::LoginRequest> request(BuildLoginRequest(0, 0, ""));
 180   GetConnectionHandler()->Init(*request, NULL);
 181   OnConnectDone(connect_result_);
 182   if (!NextRetryAttempt().is_null()) {
 183     // Advance the time to the next retry time.
 184     base::TimeDelta time_till_retry =
 185         NextRetryAttempt() - tick_clock_.NowTicks();
 186     tick_clock_.Advance(time_till_retry);
 187   }
 188   --num_expected_attempts_;
 189   if (num_expected_attempts_ == 0) {
 190     connect_result_ = net::ERR_UNEXPECTED;
 191     connections_fulfilled_ = true;
 192     finished_callback_.Run();
 193   }
 194 }
 195
 196 void TestConnectionFactoryImpl::InitHandler() {
 197   EXPECT_NE(connect_result_, net::ERR_UNEXPECTED);
 198   if (!delay_login_)
 199     ConnectionHandlerCallback(net::OK);
 200 }
 201
 202 scoped_ptr<net::BackoffEntry> TestConnectionFactoryImpl::CreateBackoffEntry(
 203     const net::BackoffEntry::Policy* const policy) {
 204   return scoped_ptr<net::BackoffEntry>(new TestBackoffEntry(&tick_clock_));
 205 }
 206
 207 scoped_ptr<ConnectionHandler>
 208 TestConnectionFactoryImpl::CreateConnectionHandler(
 209     base::TimeDelta read_timeout,
 210     const ConnectionHandler::ProtoReceivedCallback& read_callback,
 211     const ConnectionHandler::ProtoSentCallback& write_callback,
 212     const ConnectionHandler::ConnectionChangedCallback& connection_callback) {
 213   fake_handler_ = new FakeConnectionHandler(
 214       base::Bind(&ReadContinuation),
 215       base::Bind(&WriteContinuation));
 216   return make_scoped_ptr<ConnectionHandler>(fake_handler_);
 217 }
 218
 219 base::TimeTicks TestConnectionFactoryImpl::NowTicks() {
 220   return tick_clock_.NowTicks();
 221 }
 222
 223 void TestConnectionFactoryImpl::SetConnectResult(int connect_result) {
 224   DCHECK_NE(connect_result, net::ERR_UNEXPECTED);
 225   ASSERT_EQ(0, num_expected_attempts_);
 226   connections_fulfilled_ = false;
 227   connect_result_ = connect_result;
 228   num_expected_attempts_ = 1;
 229   fake_handler_->ExpectOutgoingMessage(
 230       MCSMessage(kLoginRequestTag,
 231                  BuildLoginRequest(0, 0, "").PassAs<
 232                      const google::protobuf::MessageLite>()));
 233 }
 234
 235 void TestConnectionFactoryImpl::SetMultipleConnectResults(
 236     int connect_result,
 237     int num_expected_attempts) {
 238   DCHECK_NE(connect_result, net::ERR_UNEXPECTED);
 239   DCHECK_GT(num_expected_attempts, 0);
 240   ASSERT_EQ(0, num_expected_attempts_);
 241   connections_fulfilled_ = false;
 242   connect_result_ = connect_result;
 243   num_expected_attempts_ = num_expected_attempts;
 244   for (int i = 0 ; i < num_expected_attempts; ++i) {
 245     fake_handler_->ExpectOutgoingMessage(
 246         MCSMessage(kLoginRequestTag,
 247                    BuildLoginRequest(0, 0, "").PassAs<
 248                        const google::protobuf::MessageLite>()));
 249   }
 250 }
 251
 252 void TestConnectionFactoryImpl::SetDelayLogin(bool delay_login) {
 253   delay_login_ = delay_login;
 254   fake_handler_->set_fail_login(delay_login_);
 255 }
 256
 257 }  // namespace
 258
 259 class ConnectionFactoryImplTest
 260     : public testing::Test,
 261       public ConnectionFactory::ConnectionListener {
 262  public:
 263   ConnectionFactoryImplTest();
 264   virtual ~ConnectionFactoryImplTest();
 265
 266   TestConnectionFactoryImpl* factory() { return &factory_; }
 267   GURL& connected_server() { return connected_server_; }
 268
 269   void WaitForConnections();
 270
 271   // ConnectionFactory::ConnectionListener
 272   virtual void OnConnected(const GURL& current_server,
 273                            const net::IPEndPoint& ip_endpoint) OVERRIDE;
 274   virtual void OnDisconnected() OVERRIDE;
 275
 276  private:
 277   void ConnectionsComplete();
 278
 279   TestConnectionFactoryImpl factory_;
 280   base::MessageLoop message_loop_;
 281   scoped_ptr<base::RunLoop> run_loop_;
 282
 283   GURL connected_server_;
 284 };
 285
 286 ConnectionFactoryImplTest::ConnectionFactoryImplTest()
 287    : factory_(base::Bind(&ConnectionFactoryImplTest::ConnectionsComplete,
 288                          base::Unretained(this))),
 289      run_loop_(new base::RunLoop()) {
 290   factory()->SetConnectionListener(this);
 291   factory()->Initialize(
 292       ConnectionFactory::BuildLoginRequestCallback(),
 293       ConnectionHandler::ProtoReceivedCallback(),
 294       ConnectionHandler::ProtoSentCallback());
 295 }
 296 ConnectionFactoryImplTest::~ConnectionFactoryImplTest() {}
 297
 298 void ConnectionFactoryImplTest::WaitForConnections() {
 299   run_loop_->Run();
 300   run_loop_.reset(new base::RunLoop());
 301 }
 302
 303 void ConnectionFactoryImplTest::ConnectionsComplete() {
 304   if (!run_loop_)
 305     return;
 306   run_loop_->Quit();
 307 }
 308
 309 void ConnectionFactoryImplTest::OnConnected(
 310     const GURL& current_server,
 311     const net::IPEndPoint& ip_endpoint) {
 312   connected_server_ = current_server;
 313 }
 314
 315 void ConnectionFactoryImplTest::OnDisconnected() {
 316   connected_server_ = GURL();
 317 }
 318
 319 // Verify building a connection handler works.
 320 TEST_F(ConnectionFactoryImplTest, Initialize) {
 321   ConnectionHandler* handler = factory()->GetConnectionHandler();
 322   ASSERT_TRUE(handler);
 323   EXPECT_FALSE(factory()->IsEndpointReachable());
 324   EXPECT_FALSE(connected_server().is_valid());
 325 }
 326
 327 // An initial successful connection should not result in backoff.
 328 TEST_F(ConnectionFactoryImplTest, ConnectSuccess) {
 329   factory()->SetConnectResult(net::OK);
 330   factory()->Connect();
 331   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 332   EXPECT_EQ(factory()->GetCurrentEndpoint(), BuildEndpoints()[0]);
 333   EXPECT_TRUE(factory()->IsEndpointReachable());
 334   EXPECT_TRUE(connected_server().is_valid());
 335 }
 336
 337 // A connection failure should result in backoff, and attempting the fallback
 338 // endpoint next.
 339 TEST_F(ConnectionFactoryImplTest, ConnectFail) {
 340   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 341   factory()->Connect();
 342   EXPECT_FALSE(factory()->NextRetryAttempt().is_null());
 343   EXPECT_EQ(factory()->GetCurrentEndpoint(), BuildEndpoints()[1]);
 344   EXPECT_FALSE(factory()->IsEndpointReachable());
 345   EXPECT_FALSE(connected_server().is_valid());
 346 }
 347
 348 // A connection success after a failure should reset backoff.
 349 TEST_F(ConnectionFactoryImplTest, FailThenSucceed) {
 350   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 351   base::TimeTicks connect_time = factory()->tick_clock()->NowTicks();
 352   factory()->Connect();
 353   WaitForConnections();
 354   EXPECT_FALSE(factory()->IsEndpointReachable());
 355   EXPECT_FALSE(connected_server().is_valid());
 356   base::TimeTicks retry_time = factory()->NextRetryAttempt();
 357   EXPECT_FALSE(retry_time.is_null());
 358   EXPECT_GE((retry_time - connect_time).InMilliseconds(), CalculateBackoff(1));
 359   factory()->SetConnectResult(net::OK);
 360   WaitForConnections();
 361   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 362   EXPECT_TRUE(factory()->IsEndpointReachable());
 363   EXPECT_TRUE(connected_server().is_valid());
 364 }
 365
 366 // Multiple connection failures should retry with an exponentially increasing
 367 // backoff, then reset on success.
 368 TEST_F(ConnectionFactoryImplTest, MultipleFailuresThenSucceed) {
 369   const int kNumAttempts = 5;
 370   factory()->SetMultipleConnectResults(net::ERR_CONNECTION_FAILED,
 371                                        kNumAttempts);
 372
 373   base::TimeTicks connect_time = factory()->tick_clock()->NowTicks();
 374   factory()->Connect();
 375   WaitForConnections();
 376   EXPECT_FALSE(factory()->IsEndpointReachable());
 377   EXPECT_FALSE(connected_server().is_valid());
 378   base::TimeTicks retry_time = factory()->NextRetryAttempt();
 379   EXPECT_FALSE(retry_time.is_null());
 380   EXPECT_GE((retry_time - connect_time).InMilliseconds(),
 381             CalculateBackoff(kNumAttempts));
 382
 383   factory()->SetConnectResult(net::OK);
 384   WaitForConnections();
 385   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 386   EXPECT_TRUE(factory()->IsEndpointReachable());
 387   EXPECT_TRUE(connected_server().is_valid());
 388 }
 389
 390 // Network change events should trigger canary connections.
 391 TEST_F(ConnectionFactoryImplTest, FailThenNetworkChangeEvent) {
 392   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 393   factory()->Connect();
 394   WaitForConnections();
 395   base::TimeTicks initial_backoff = factory()->NextRetryAttempt();
 396   EXPECT_FALSE(initial_backoff.is_null());
 397
 398   factory()->SetConnectResult(net::ERR_FAILED);
 399   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_WIFI);
 400   WaitForConnections();
 401
 402   // Backoff should increase.
 403   base::TimeTicks next_backoff = factory()->NextRetryAttempt();
 404   EXPECT_GT(next_backoff, initial_backoff);
 405   EXPECT_FALSE(factory()->IsEndpointReachable());
 406 }
 407
 408 // Verify that we reconnect even if a canary succeeded then disconnected while
 409 // a backoff was pending.
 410 TEST_F(ConnectionFactoryImplTest, CanarySucceedsThenDisconnects) {
 411   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 412   factory()->Connect();
 413   WaitForConnections();
 414   base::TimeTicks initial_backoff = factory()->NextRetryAttempt();
 415   EXPECT_FALSE(initial_backoff.is_null());
 416
 417   factory()->SetConnectResult(net::OK);
 418   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_ETHERNET);
 419   WaitForConnections();
 420   EXPECT_TRUE(factory()->IsEndpointReachable());
 421   EXPECT_TRUE(connected_server().is_valid());
 422
 423   factory()->SetConnectResult(net::OK);
 424   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 425   EXPECT_FALSE(factory()->IsEndpointReachable());
 426   EXPECT_FALSE(connected_server().is_valid());
 427   WaitForConnections();
 428   EXPECT_TRUE(factory()->IsEndpointReachable());
 429   EXPECT_TRUE(connected_server().is_valid());
 430 }
 431
 432 // Verify that if a canary connects, but hasn't finished the handshake, a
 433 // pending backoff attempt doesn't interrupt the connection.
 434 TEST_F(ConnectionFactoryImplTest, CanarySucceedsRetryDuringLogin) {
 435   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 436   factory()->Connect();
 437   WaitForConnections();
 438   base::TimeTicks initial_backoff = factory()->NextRetryAttempt();
 439   EXPECT_FALSE(initial_backoff.is_null());
 440
 441   factory()->SetDelayLogin(true);
 442   factory()->SetConnectResult(net::OK);
 443   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_WIFI);
 444   WaitForConnections();
 445   EXPECT_FALSE(factory()->IsEndpointReachable());
 446
 447   // Pump the loop, to ensure the pending backoff retry has no effect.
 448   base::MessageLoop::current()->PostDelayedTask(
 449       FROM_HERE,
 450       base::MessageLoop::QuitClosure(),
 451       base::TimeDelta::FromMilliseconds(1));
 452   WaitForConnections();
 453 }
 454
 455 // Fail after successful connection via signal reset.
 456 TEST_F(ConnectionFactoryImplTest, FailViaSignalReset) {
 457   factory()->SetConnectResult(net::OK);
 458   factory()->Connect();
 459   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 460
 461   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 462   EXPECT_FALSE(factory()->NextRetryAttempt().is_null());
 463   EXPECT_FALSE(factory()->IsEndpointReachable());
 464 }
 465
 466 TEST_F(ConnectionFactoryImplTest, IgnoreResetWhileConnecting) {
 467   factory()->SetConnectResult(net::OK);
 468   factory()->Connect();
 469   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 470
 471   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 472   base::TimeTicks retry_time = factory()->NextRetryAttempt();
 473   EXPECT_FALSE(retry_time.is_null());
 474   EXPECT_FALSE(factory()->IsEndpointReachable());
 475
 476   const int kNumAttempts = 5;
 477   for (int i = 0; i < kNumAttempts; ++i)
 478     factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 479   EXPECT_EQ(retry_time, factory()->NextRetryAttempt());
 480   EXPECT_FALSE(factory()->IsEndpointReachable());
 481 }
 482
 483 // Go into backoff due to connection failure. On successful connection, receive
 484 // a signal reset. The original backoff should be restored and extended, rather
 485 // than a new backoff starting from scratch.
 486 TEST_F(ConnectionFactoryImplTest, SignalResetRestoresBackoff) {
 487   factory()->SetConnectResult(net::ERR_CONNECTION_FAILED);
 488   base::TimeTicks connect_time = factory()->tick_clock()->NowTicks();
 489   factory()->Connect();
 490   WaitForConnections();
 491   base::TimeTicks retry_time = factory()->NextRetryAttempt();
 492   EXPECT_FALSE(retry_time.is_null());
 493
 494   factory()->SetConnectResult(net::OK);
 495   connect_time = factory()->tick_clock()->NowTicks();
 496   WaitForConnections();
 497   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 498
 499   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 500   EXPECT_FALSE(factory()->IsEndpointReachable());
 501   EXPECT_FALSE(connected_server().is_valid());
 502   EXPECT_NE(retry_time, factory()->NextRetryAttempt());
 503   retry_time = factory()->NextRetryAttempt();
 504   EXPECT_FALSE(retry_time.is_null());
 505   EXPECT_GE((retry_time - connect_time).InMilliseconds(),
 506             CalculateBackoff(2));
 507
 508   factory()->SetConnectResult(net::OK);
 509   connect_time = factory()->tick_clock()->NowTicks();
 510   factory()->tick_clock()->Advance(
 511       factory()->NextRetryAttempt() - connect_time);
 512   WaitForConnections();
 513   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 514   EXPECT_TRUE(factory()->IsEndpointReachable());
 515   EXPECT_TRUE(connected_server().is_valid());
 516
 517   factory()->SignalConnectionReset(ConnectionFactory::SOCKET_FAILURE);
 518   EXPECT_NE(retry_time, factory()->NextRetryAttempt());
 519   retry_time = factory()->NextRetryAttempt();
 520   EXPECT_FALSE(retry_time.is_null());
 521   EXPECT_GE((retry_time - connect_time).InMilliseconds(),
 522             CalculateBackoff(3));
 523   EXPECT_FALSE(factory()->IsEndpointReachable());
 524   EXPECT_FALSE(connected_server().is_valid());
 525 }
 526
 527 // When the network is disconnected, close the socket and suppress further
 528 // connection attempts until the network returns.
 529 TEST_F(ConnectionFactoryImplTest, SuppressConnectWhenNoNetwork) {
 530   factory()->SetConnectResult(net::OK);
 531   factory()->Connect();
 532   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 533   EXPECT_TRUE(factory()->IsEndpointReachable());
 534
 535   // Advance clock so the login window reset isn't encountered.
 536   factory()->tick_clock()->Advance(base::TimeDelta::FromSeconds(11));
 537
 538   // Will trigger reset, but will not attempt a new connection.
 539   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_NONE);
 540   EXPECT_FALSE(factory()->IsEndpointReachable());
 541   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 542
 543   // When the network returns, attempt to connect.
 544   factory()->SetConnectResult(net::OK);
 545   factory()->OnNetworkChanged(net::NetworkChangeNotifier::CONNECTION_4G);
 546   WaitForConnections();
 547
 548   EXPECT_TRUE(factory()->IsEndpointReachable());
 549   EXPECT_TRUE(factory()->NextRetryAttempt().is_null());
 550 }
 551
 552 }  // namespace gcm