Expose RTT and downlink bandwidth using experimental Javascript API

content/browser/net_info_browsertest.cc

Index: content/browser/net_info_browsertest.cc
diff --git a/content/browser/net_info_browsertest.cc b/content/browser/net_info_browsertest.cc
index 135ac36037517d3752ffb39f2d6df92059f6e029..9178b4bdb8dc6d162045e90235de190c16b3f27d 100644
--- a/content/browser/net_info_browsertest.cc
+++ b/content/browser/net_info_browsertest.cc
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <map>
+#include <string>
+
 #include "base/command_line.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
@@ -15,6 +18,7 @@
 #include "content/shell/browser/shell.h"
 #include "net/base/network_change_notifier.h"
 #include "net/base/network_change_notifier_factory.h"
+#include "net/log/test_net_log.h"
 #include "net/nqe/network_quality_estimator_test_util.h"
 
 namespace content {
@@ -144,21 +148,143 @@ IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, TwoRenderViewsInOneProcess) {
   EXPECT_FALSE(RunScriptExtractBool("getOnLine()"));
 }
 
+// Verify that when the network quality notifications are not sent, the
+// Javascript API returns invalid estimate.
+IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest,
+                       NetworkQualityEstimatorNotInitialized) {
+  base::HistogramTester histogram_tester;
+  net::TestNetworkQualityEstimator estimator(
+      nullptr, std::map<std::string, std::string>(), false, false, true, true,
+      base::MakeUnique<net::BoundTestNetLog>());
+  NetworkQualityObserverImpl impl(&estimator);
+
+  NavigateToURL(shell(), content::GetTestUrl("", "net_info.html"));

[nasko, 2017/05/12 23:29:54]

Why not load this through the embedded_test_server()? Does it need to be a
file:// based navigation? If yes, please add a comment to ensure it is known
why.

[tbansal1, 2017/05/15 18:05:03]

Done.

+  base::RunLoop().RunUntilIdle();

[nasko, 2017/05/12 23:29:54]

Why do we need this? NavigateToURL is waiting for the navigation to complete. If
you need to wait for something else, it should be an explicit wait for that
event.

[tbansal1, 2017/05/15 18:05:03]

Done. There are still couple of RunUntilIdle() but they are at places where they
are not preceded by NavigateToURL().

+  EXPECT_EQ(-1, RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(-0.001, RunScriptExtractDouble("getDownlink()"));
+}
+
 // Make sure the changes in the network quality are notified to the render
-// thread.
+// thread, and the changed network quality is accessible via Javascript API.
 IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkQualityChangeNotified) {
   base::HistogramTester histogram_tester;
-  net::TestNetworkQualityEstimator estimator;
+  net::TestNetworkQualityEstimator estimator(
+      nullptr, std::map<std::string, std::string>(), false, false, true, true,
+      base::MakeUnique<net::BoundTestNetLog>());
   NetworkQualityObserverImpl impl(&estimator);
-  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
-      net::nqe::internal::NetworkQuality(base::TimeDelta::FromSeconds(1),
-                                         base::TimeDelta::FromSeconds(2), 3));
 
+  net::nqe::internal::NetworkQuality network_quality_1(
+      base::TimeDelta::FromSeconds(1), base::TimeDelta::FromSeconds(2), 300);
+  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
+      network_quality_1);
   NavigateToURL(shell(), content::GetTestUrl("", "net_info.html"));
 
+  base::RunLoop().RunUntilIdle();

[nasko, 2017/05/12 23:29:54]

Same here, let's wait for something explicit.

[tbansal1, 2017/05/15 18:05:03]

Done.

   FetchHistogramsFromChildProcesses();
   EXPECT_FALSE(
       histogram_tester.GetAllSamples("NQE.RenderThreadNotified").empty());
+
+  EXPECT_EQ(network_quality_1.transport_rtt().InMilliseconds(),
+            RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(
+      static_cast<double>(network_quality_1.downstream_throughput_kbps()) /
+          1000,
+      RunScriptExtractDouble("getDownlink()"));
+
+  // Verify that the network quality change is accessible via Javascript API.
+  net::nqe::internal::NetworkQuality network_quality_2(
+      base::TimeDelta::FromSeconds(10), base::TimeDelta::FromSeconds(20), 3000);
+  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
+      network_quality_2);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(network_quality_2.transport_rtt().InMilliseconds(),
+            RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(
+      static_cast<double>(network_quality_2.downstream_throughput_kbps()) /
+          1000,
+      RunScriptExtractDouble("getDownlink()"));
+}
+
+// Make sure the changes in the network quality are rounded to the nearest
+// 25 milliseconds or 25 kbps.
+IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkQualityChangeRounded) {
+  base::HistogramTester histogram_tester;
+  net::TestNetworkQualityEstimator estimator(
+      std::unique_ptr<net::ExternalEstimateProvider>(),
+      std::map<std::string, std::string>(), false, false, true, true,
+      base::MakeUnique<net::BoundTestNetLog>());
+  NetworkQualityObserverImpl impl(&estimator);
+
+  // Verify that the network quality is rounded properly.
+  net::nqe::internal::NetworkQuality network_quality_1(
+      base::TimeDelta::FromMilliseconds(123),
+      base::TimeDelta::FromMilliseconds(212), 303);
+  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
+      network_quality_1);
+  NavigateToURL(shell(), content::GetTestUrl("", "net_info.html"));
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(200, RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(0.300, RunScriptExtractDouble("getDownlink()"));
+
+  net::nqe::internal::NetworkQuality network_quality_2(
+      base::TimeDelta::FromMilliseconds(123),
+      base::TimeDelta::FromMilliseconds(1217), 1317);
+  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
+      network_quality_2);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(1225, RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(1.325, RunScriptExtractDouble("getDownlink()"));
+
+  net::nqe::internal::NetworkQuality network_quality_3(
+      base::TimeDelta::FromMilliseconds(12),
+      base::TimeDelta::FromMilliseconds(12), 12);
+  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
+      network_quality_3);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(0, RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(0, RunScriptExtractDouble("getDownlink()"));
+}
+
+// Make sure the minor changes (<10%) in the network quality are not notified.
+IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, NetworkQualityChangeNotNotified) {
+  base::HistogramTester histogram_tester;
+  net::TestNetworkQualityEstimator estimator(
+      nullptr, std::map<std::string, std::string>(), false, false, true, true,
+      base::MakeUnique<net::BoundTestNetLog>());
+  NetworkQualityObserverImpl impl(&estimator);
+
+  // Verify that the network quality is rounded properly.
+  net::nqe::internal::NetworkQuality network_quality_1(
+      base::TimeDelta::FromMilliseconds(1123),
+      base::TimeDelta::FromMilliseconds(1212), 1303);
+  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
+      network_quality_1);
+  NavigateToURL(shell(), content::GetTestUrl("", "net_info.html"));
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(1200, RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(1.300, RunScriptExtractDouble("getDownlink()"));
+
+  // All the 3 metrics change by less than 10%. So, the observers are not
+  // notified.
+  net::nqe::internal::NetworkQuality network_quality_2(
+      base::TimeDelta::FromMilliseconds(1223),
+      base::TimeDelta::FromMilliseconds(1312), 1403);
+  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
+      network_quality_2);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(1200, RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(1.300, RunScriptExtractDouble("getDownlink()"));
+
+  // Transport RTT has changed by more than 10% from the last notified value of
+  // |network_quality_1|. The observers should be notified.
+  net::nqe::internal::NetworkQuality network_quality_3(
+      base::TimeDelta::FromMilliseconds(1223),
+      base::TimeDelta::FromMilliseconds(2312), 1403);
+  estimator.NotifyObserversOfRTTOrThroughputEstimatesComputed(
+      network_quality_3);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(2300, RunScriptExtractDouble("getRtt()"));
+  EXPECT_EQ(1.400, RunScriptExtractDouble("getDownlink()"));
 }
 
 }  // namespace content