1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154
  155
  156
  157
  158
  159
  160
  161
  162
  163
  164
  165
  166
  167
  168
  169
  170
  171
  172
  173
  174
  175
  176
  177
  178
  179
  180
  181
  182
  183
  184
  185
  186
  187
  188
  189
  190
  191
  192
  193
  194
  195
  196
  197
  198
  199
  200
  201
  202
  203
  204
  205
  206
  207
  208
  209
  210
  211
  212
  213
  214
  215
  216
  217
  218
  219
  220
  221
  222
  223
  224
  225
  226
  227
  228
  229
  230
  231
  232
  233
  234
  235
  236
  237
  238
  239
  240
  241
  242
  243
  244
  245
  246
  247
  248
  249
  250
  251
  252
  253
  254
  255
  256
  257
  258
  259
  260
  261
  262
  263
  264
  265
  266
  267
  268
  269
  270
  271
  272
  273
  274
  275
  276
  277
  278
  279
  280
  281
  282
  283
  284
  285
  286
  287
  288
  289
  290
  291
  292
  293
  294
  295
  296
  297
  298
  299
  300
  301
  302
  303
  304
  305
  306
  307
  308
  309
  310
  311
  312
  313
  314
  315
  316
  317
  318
  319
  320
  321
  322
  323
  324
  325
  326
  327
  328
  329
  330
  331
  332
  333
  334
  335
  336
  337
  338
  339
  340
  341
  342
  343
  344
  345
  346
  347
  348
  349
  350
  351
  352
  353
  354
  355
  356
  357
  358
  359
  360
  361
  362
  363
  364
  365
  366
  367
  368
  369
  370
  371
  372
  373
  374
  375
  376
  377
  378
  379
  380
  381
  382
  383
  384
  385
  386
  387
  388
  389
  390
  391
  392
  393
  394
  395
  396
  397
  398
  399
  400
  401
  402
  403
  404
  405
  406
  407
  408
  409
  410
  411
  412
  413
  414
  415
  416
  417
  418
  419
  420
  421
  422
  423
  424
  425
  426
  427
  428
  429
  430
  431
  432
  433
  434
  435
  436
  437
  438
  439
  440
  441
  442
  443
  444
  445
  446
  447
  448
  449
  450
  451
  452
  453
  454
  455
  456
  457
  458
  459
  460
  461
  462
  463
  464
  465
  466
  467
  468
  469
  470
  471
  472
  473
  474
  475
  476
  477
  478
  479
  480
  481
  482
  483
  484
  485

content / browser / net_info_browsertest.cc [blame]

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <cmath>  // For std::modf.
#include <map>
#include <string>

#include "base/command_line.h"
#include "base/run_loop.h"
#include "base/strings/string_number_conversions.h"
#include "base/test/metrics/histogram_tester.h"
#include "build/build_config.h"
#include "content/browser/network/network_quality_observer_impl.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/common/content_switches.h"
#include "content/public/test/browser_test.h"
#include "content/public/test/browser_test_utils.h"
#include "content/public/test/content_browser_test.h"
#include "content/public/test/content_browser_test_utils.h"
#include "content/shell/browser/shell.h"
#include "net/base/network_change_notifier.h"
#include "net/base/network_change_notifier_factory.h"
#include "net/dns/mock_host_resolver.h"
#include "net/log/test_net_log.h"
#include "net/nqe/effective_connection_type.h"
#include "services/network/test/test_network_quality_tracker.h"

namespace {

// Returns the total count of samples in |histogram|.
int GetTotalSampleCount(base::HistogramTester* tester,
                        const std::string& histogram) {
  int count = 0;
  std::vector<base::Bucket> buckets = tester->GetAllSamples(histogram);
  for (const auto& bucket : buckets)
    count += bucket.count;
  return count;
}

void VerifyRtt(base::TimeDelta expected_rtt, int32_t got_rtt_milliseconds) {
  EXPECT_EQ(0, got_rtt_milliseconds % 50)
      << " got_rtt_milliseconds=" << got_rtt_milliseconds;

  if (expected_rtt > base::Milliseconds(3000))
    expected_rtt = base::Milliseconds(3000);

  // The difference between the actual and the estimate value should be within
  // 10%. Add 50 (bucket size used in Blink) to account for the cases when the
  // sample may spill over to the next bucket due to the added noise of 10%.
  // For example, if sample is 300 msec, after adding noise, it may become 330,
  // and after rounding off, it would spill over to the next bucket of 350 msec.
  EXPECT_GE((expected_rtt.InMilliseconds() * 0.1) + 50,
            std::abs(expected_rtt.InMilliseconds() - got_rtt_milliseconds))
      << " expected_rtt=" << expected_rtt
      << " got_rtt_milliseconds=" << got_rtt_milliseconds;
}

void VerifyDownlinkKbps(double expected_kbps, double got_kbps) {
  // First verify that |got_kbps| is a multiple of 50.
  int quotient = static_cast<int>(got_kbps / 50);
  // |mod| is the remainder left after dividing |got_kbps| by 50 while
  // restricting the quotient to integer.  For example, if |got_kbps| is
  // 1050, then mod will be 0. If |got_kbps| is 1030, mod will be 30.
  double mod = got_kbps - 50 * quotient;
  EXPECT_LE(0.0, mod);
  EXPECT_GT(50.0, mod);
  // It is possible that |mod| is not exactly 0 because of floating point
  // computations. e.g., |got_kbps| may be 99.999999, in which case |mod|
  // will be 49.999999.
  EXPECT_TRUE(mod < (1e-5) || (50 - mod) < 1e-5) << " got_kbps=" << got_kbps;

  if (expected_kbps > 10000)
    expected_kbps = 10000;

  // The difference between the actual and the estimate value should be within
  // 10%. Add 50 (bucket size used in Blink) to account for the cases when the
  // sample may spill over to the next bucket due to the added noise of 10%.
  // For example, if sample is 300 kbps, after adding noise, it may become 330,
  // and after rounding off, it would spill over to the next bucket of 350 kbps.
  EXPECT_GE((expected_kbps * 0.1) + 50, std::abs(expected_kbps - got_kbps))
      << " expected_kbps=" << expected_kbps << " got_kbps=" << got_kbps;
}

class MockNetworkChangeNotifierWifi : public net::NetworkChangeNotifier {
 public:
  void GetCurrentMaxBandwidthAndConnectionType(
      double* max_bandwidth_mbps,
      ConnectionType* connection_type) const override {
    *connection_type = NetworkChangeNotifier::CONNECTION_WIFI;
    *max_bandwidth_mbps =
        net::NetworkChangeNotifier::GetMaxBandwidthMbpsForConnectionSubtype(
            net::NetworkChangeNotifier::SUBTYPE_WIFI_N);
  }
  ConnectionType GetCurrentConnectionType() const override {
    return NetworkChangeNotifier::CONNECTION_WIFI;
  }
};

}  // namespace

namespace content {

class NetInfoBrowserTest : public content::ContentBrowserTest {
 public:
  NetInfoBrowserTest()
      : test_network_quality_tracker_(
            std::make_unique<network::TestNetworkQualityTracker>()) {}

  network::NetworkQualityTracker* GetNetworkQualityTracker() const {
    return test_network_quality_tracker_.get();
  }

 protected:
  void SetUpCommandLine(base::CommandLine* command_line) override {
    // TODO(jkarlin): Once NetInfo is enabled on all platforms remove this
    // switch.
    command_line->AppendSwitch(switches::kEnableNetworkInformationDownlinkMax);

    // TODO(jkarlin): Remove this once downlinkMax is no longer
    // experimental.
    command_line->AppendSwitch(
        switches::kEnableExperimentalWebPlatformFeatures);
  }

  void SetUp() override {
    net::NetworkChangeNotifier::SetTestNotificationsOnly(true);

    content::ContentBrowserTest::SetUp();
  }

  void SetUpOnMainThread() override {
    host_resolver()->AddRule("*", "127.0.0.1");
    base::RunLoop().RunUntilIdle();
  }

  static void SetConnectionType(
      net::NetworkChangeNotifier::ConnectionType type,
      net::NetworkChangeNotifier::ConnectionSubtype subtype) {
    net::NetworkChangeNotifier::NotifyObserversOfMaxBandwidthChangeForTests(
        net::NetworkChangeNotifier::GetMaxBandwidthMbpsForConnectionSubtype(
            subtype),
        type);
    base::RunLoop().RunUntilIdle();
  }

  std::string RunScriptExtractString(const std::string& script) {
    return EvalJs(shell(), script).ExtractString();
  }

  bool RunScriptExtractBool(const std::string& script) {
    return EvalJs(shell(), script).ExtractBool();
  }

  double RunScriptExtractDouble(const std::string& script) {
    return EvalJs(shell(), script).ExtractDouble();
  }

  int RunScriptExtractInt(const std::string& script) {
    return EvalJs(shell(), script).ExtractInt();
  }

 private:
  std::unique_ptr<network::TestNetworkQualityTracker>
      test_network_quality_tracker_;
};

// Make sure the type is correct when the page is first opened.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, VerifyNetworkStateInitialized) {
  // Mock out the NCN.
  net::NetworkChangeNotifier::DisableForTest disable_for_test;
  MockNetworkChangeNotifierWifi mock_notifier;

  EXPECT_TRUE(NavigateToURL(shell(), content::GetTestUrl("", "net_info.html")));
  EXPECT_TRUE(RunScriptExtractBool("getOnLine()"));
  EXPECT_EQ("wifi", RunScriptExtractString("getType()"));
  EXPECT_EQ(net::NetworkChangeNotifier::GetMaxBandwidthMbpsForConnectionSubtype(
                net::NetworkChangeNotifier::SUBTYPE_WIFI_N),
            RunScriptExtractDouble("getDownlinkMax()"));
}

// Make sure that type changes in the browser make their way to
// navigator.connection.type.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkChangePlumbsToNavigator) {
  EXPECT_TRUE(NavigateToURL(shell(), content::GetTestUrl("", "net_info.html")));
  SetConnectionType(net::NetworkChangeNotifier::CONNECTION_WIFI,
                    net::NetworkChangeNotifier::SUBTYPE_WIFI_N);
  EXPECT_EQ("wifi", RunScriptExtractString("getType()"));
  EXPECT_EQ(net::NetworkChangeNotifier::GetMaxBandwidthMbpsForConnectionSubtype(
                net::NetworkChangeNotifier::SUBTYPE_WIFI_N),
            RunScriptExtractDouble("getDownlinkMax()"));

  SetConnectionType(net::NetworkChangeNotifier::CONNECTION_ETHERNET,
                    net::NetworkChangeNotifier::SUBTYPE_GIGABIT_ETHERNET);
  EXPECT_EQ("ethernet", RunScriptExtractString("getType()"));
  EXPECT_EQ(net::NetworkChangeNotifier::GetMaxBandwidthMbpsForConnectionSubtype(
                net::NetworkChangeNotifier::SUBTYPE_GIGABIT_ETHERNET),
            RunScriptExtractDouble("getDownlinkMax()"));
}

// Make sure that type changes in the browser make their way to
// navigator.isOnline.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, IsOnline) {
  EXPECT_TRUE(NavigateToURL(shell(), content::GetTestUrl("", "net_info.html")));
  SetConnectionType(net::NetworkChangeNotifier::CONNECTION_ETHERNET,
                    net::NetworkChangeNotifier::SUBTYPE_GIGABIT_ETHERNET);
  EXPECT_TRUE(RunScriptExtractBool("getOnLine()"));
  SetConnectionType(net::NetworkChangeNotifier::CONNECTION_NONE,
                    net::NetworkChangeNotifier::SUBTYPE_NONE);
  EXPECT_FALSE(RunScriptExtractBool("getOnLine()"));
  SetConnectionType(net::NetworkChangeNotifier::CONNECTION_WIFI,
                    net::NetworkChangeNotifier::SUBTYPE_WIFI_N);
  EXPECT_TRUE(RunScriptExtractBool("getOnLine()"));
}

// Creating a new render view shouldn't reinitialize Blink's
// NetworkStateNotifier. See https://crbug.com/535081.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, TwoRenderViewsInOneProcess) {
  SetConnectionType(net::NetworkChangeNotifier::CONNECTION_ETHERNET,
                    net::NetworkChangeNotifier::SUBTYPE_GIGABIT_ETHERNET);
  EXPECT_TRUE(NavigateToURL(shell(), content::GetTestUrl("", "net_info.html")));
  EXPECT_TRUE(RunScriptExtractBool("getOnLine()"));

  SetConnectionType(net::NetworkChangeNotifier::CONNECTION_NONE,
                    net::NetworkChangeNotifier::SUBTYPE_NONE);
  EXPECT_FALSE(RunScriptExtractBool("getOnLine()"));

  // Open the same page in a new window on the same process.
  EXPECT_TRUE(ExecJs(shell(), "window.open(\"net_info.html\")"));

  // The network state should not have reinitialized to what it was when opening
  // the first window (online).
  EXPECT_FALSE(RunScriptExtractBool("getOnLine()"));
}

// Verify that when the network quality notifications are not sent, the
// Javascript API returns a valid estimate that is multiple of 50 msec and 50
// kbps.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest,
                       NetworkQualityEstimatorNotInitialized) {
  base::HistogramTester histogram_tester;
  NetworkQualityObserverImpl impl(GetNetworkQualityTracker());

  EXPECT_TRUE(embedded_test_server()->Start());
  EXPECT_TRUE(
      NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));

  // When NQE is not initialized, the javascript calls should return default
  // values.
  EXPECT_EQ(0, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(10000, RunScriptExtractDouble("getDownlink()") * 1000);
}

// Make sure the changes in the effective connection type are notified to the
// render thread.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest,
                       EffectiveConnectionTypeChangeNotified) {
  base::HistogramTester histogram_tester;
  NetworkQualityObserverImpl impl(GetNetworkQualityTracker());

  base::TimeDelta http_rtt(base::Milliseconds(1000));
  int32_t downstream_throughput_kbps = 300;
  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);

  EXPECT_TRUE(embedded_test_server()->Start());
  EXPECT_TRUE(
      NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));

  FetchHistogramsFromChildProcesses();

  int samples =
      GetTotalSampleCount(&histogram_tester, "NQE.RenderThreadNotified");
  EXPECT_LT(0, samples);

  // Change effective connection type so that the renderer process is notified.
  // Changing the effective connection type from 2G to 3G is guaranteed to
  // generate the notification to the renderers, irrespective of the current
  // effective connection type.
  GetNetworkQualityTracker()->ReportEffectiveConnectionTypeForTesting(
      net::EFFECTIVE_CONNECTION_TYPE_2G);
  EXPECT_EQ("2g", RunScriptExtractString("getEffectiveType()"));

  GetNetworkQualityTracker()->ReportEffectiveConnectionTypeForTesting(
      net::EFFECTIVE_CONNECTION_TYPE_3G);
  EXPECT_EQ("3g", RunScriptExtractString("getEffectiveType()"));

  FetchHistogramsFromChildProcesses();
  EXPECT_GT(GetTotalSampleCount(&histogram_tester, "NQE.RenderThreadNotified"),
            samples);
}

// Make sure the changes in the network quality are notified to the render
// thread, and the changed network quality is accessible via Javascript API.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkQualityChangeNotified) {
  base::HistogramTester histogram_tester;
  NetworkQualityObserverImpl impl(GetNetworkQualityTracker());

  base::TimeDelta http_rtt(base::Milliseconds(1000));
  int32_t downstream_throughput_kbps = 300;

  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);

  EXPECT_TRUE(embedded_test_server()->Start());
  EXPECT_TRUE(
      NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));

  FetchHistogramsFromChildProcesses();
  EXPECT_FALSE(
      histogram_tester.GetAllSamples("NQE.RenderThreadNotified").empty());

  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);

  // Verify that the network quality change is accessible via Javascript API.
  http_rtt = base::Seconds(10);
  downstream_throughput_kbps = 3000;
  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);
  base::RunLoop().RunUntilIdle();
  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);
}

// Make sure the changes in the network quality are rounded to the nearest
// 50 milliseconds or 50 kbps.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkQualityChangeRounded) {
  base::HistogramTester histogram_tester;
  NetworkQualityObserverImpl impl(GetNetworkQualityTracker());

  // Verify that the network quality is rounded properly.
  base::TimeDelta http_rtt(base::Milliseconds(103));
  int32_t downstream_throughput_kbps = 8303;
  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);

  EXPECT_TRUE(embedded_test_server()->Start());
  EXPECT_TRUE(
      NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));
  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);

  http_rtt = base::Milliseconds(1103);
  downstream_throughput_kbps = 1307;
  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);
  base::RunLoop().RunUntilIdle();
  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);

  http_rtt = base::Milliseconds(2112);
  downstream_throughput_kbps = 2112;
  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);
  base::RunLoop().RunUntilIdle();
  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);
}

// Make sure the network quality are rounded down when it exceeds the upper
// limit.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkQualityChangeUpperLimit) {
  base::HistogramTester histogram_tester;
  NetworkQualityObserverImpl impl(GetNetworkQualityTracker());

  base::TimeDelta http_rtt(base::Milliseconds(12003));
  int32_t downstream_throughput_kbps = 30300;

  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);

  EXPECT_TRUE(embedded_test_server()->Start());
  EXPECT_TRUE(
      NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));
  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);
}

// Make sure the noise added to the network quality varies with the hostname.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkQualityRandomized) {
  base::HistogramTester histogram_tester;
  NetworkQualityObserverImpl impl(GetNetworkQualityTracker());

  base::TimeDelta http_rtt(base::Milliseconds(2000));
  int32_t downstream_throughput_kbps = 3000;

  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);

  EXPECT_TRUE(embedded_test_server()->Start());

  EXPECT_TRUE(
      NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));
  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);

  const int32_t rtt_noise_milliseconds = RunScriptExtractInt("getRtt()") - 2000;
  const int32_t downlink_noise_kbps =
      RunScriptExtractDouble("getDownlink()") * 1000 - 3000;

  // When the hostname is not changed, the noise should not change.
  EXPECT_TRUE(
      NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));
  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);
  EXPECT_EQ(rtt_noise_milliseconds, RunScriptExtractInt("getRtt()") - 2000);
  EXPECT_EQ(downlink_noise_kbps,
            RunScriptExtractDouble("getDownlink()") * 1000 - 3000);

  // Verify that changing the hostname changes the noise. It is possible that
  // the hash of a different host also maps to the same bucket among 20 buckets.
  // Try 10 different hosts. This reduces the probability of failure of this
  // test to (1/20)^10 = 9,7 * 10^-14.
  for (size_t i = 0; i < 10; ++i) {
    // The noise added is a function of the hostname. Varying the hostname
    // should vary the noise.
    std::string fake_hostname = "example" + base::NumberToString(i) + ".com";
    EXPECT_TRUE(NavigateToURL(shell(), embedded_test_server()->GetURL(
                                           fake_hostname, "/net_info.html")));
    VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
    VerifyDownlinkKbps(downstream_throughput_kbps,
                       RunScriptExtractDouble("getDownlink()") * 1000);

    int32_t new_rtt_noise_milliseconds = RunScriptExtractInt("getRtt()") - 2000;
    int32_t new_downlink_noise_kbps =
        RunScriptExtractDouble("getDownlink()") * 1000 - 3000;

    if (rtt_noise_milliseconds != new_rtt_noise_milliseconds &&
        downlink_noise_kbps != new_downlink_noise_kbps) {
      return;
    }
  }
  NOTREACHED_IN_MIGRATION()
      << "Noise not added to the network quality estimates";
}

// Make sure the minor changes (<10%) in the network quality are not notified.
IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkQualityChangeNotNotified) {
  base::HistogramTester histogram_tester;
  NetworkQualityObserverImpl impl(GetNetworkQualityTracker());

  // Verify that the network quality is rounded properly.
  base::TimeDelta http_rtt(base::Milliseconds(1123));
  int32_t downstream_throughput_kbps = 1303;
  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);

  EXPECT_TRUE(embedded_test_server()->Start());
  EXPECT_TRUE(
      NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));
  VerifyRtt(http_rtt, RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(downstream_throughput_kbps,
                     RunScriptExtractDouble("getDownlink()") * 1000);

  // All the 3 metrics change by less than 10%. So, the observers are not
  // notified.
  http_rtt = base::Milliseconds(1223);
  downstream_throughput_kbps = 1403;
  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);
  base::RunLoop().RunUntilIdle();
  VerifyRtt(base::Milliseconds(1100), RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(1300, RunScriptExtractDouble("getDownlink()") * 1000);

  // HTTP RTT has changed by more than 10% from the last notified value of
  // |network_quality_1|. The observers should be notified.
  http_rtt = base::Milliseconds(2223);
  downstream_throughput_kbps = 1403;
  GetNetworkQualityTracker()->ReportRTTsAndThroughputForTesting(
      http_rtt, downstream_throughput_kbps);
  base::RunLoop().RunUntilIdle();
  VerifyRtt(base::Milliseconds(2200), RunScriptExtractInt("getRtt()"));
  VerifyDownlinkKbps(1400, RunScriptExtractDouble("getDownlink()") * 1000);
}

}  // namespace content