NetInfo: Slight update to the default network quality value

content/browser/net_info_browsertest.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 <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/histogram_tester.h"
 #include "build/build_config.h"
 #include "content/browser/net/network_quality_observer_impl.h"
 #include "content/public/common/content_switches.h"
@@ skipping 142 matching lines @@
 
   // Open the same page in a new window on the same process.
   EXPECT_TRUE(ExecuteScript(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 invalid estimate.
+// Javascript API returns a valid estimate that is multiple of 25 msec and 25
+// kbps.
 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);
 
   EXPECT_TRUE(embedded_test_server()->Start());
   EXPECT_TRUE(
       NavigateToURL(shell(), embedded_test_server()->GetURL("/net_info.html")));
 
   EXPECT_EQ(0, RunScriptExtractDouble("getRtt()"));

[jkarlin, 2017/05/31 17:44:22]

Doesn't rtt return an unsigned long long?

[tbansal1, 2017/06/01 20:41:52]

Done.

-  EXPECT_EQ(std::numeric_limits<double>::infinity(),
-            RunScriptExtractDouble("getDownlink()"));
+  EXPECT_EQ(0, static_cast<int>(RunScriptExtractDouble("getRtt()")) % 25);

[jkarlin, 2017/05/31 17:44:22]

ditto, and everywhere else in this file.

[tbansal1, 2017/06/01 20:41:52]

Done.

+
+  double downlink_mbps = RunScriptExtractDouble("getDownlink()");
+  EXPECT_LE(0, downlink_mbps);
+
+  double fraction_part, int_part;
+  fraction_part = std::modf(downlink_mbps, &int_part);
+  // If |fraction_part| is 0, it implies |downlink_mbps| is a multiple of 1
+  // Mbps, and hence it is a multiple of 25 kbps.
+  EXPECT_TRUE(static_cast<int>(downlink_mbps * 1000) % 25 == 0 ||
+              fraction_part == 0);
+
   EXPECT_EQ("4g", RunScriptExtractString("getEffectiveType()"));
 }
 
 // Make sure the changes in the effective connection typeare notified to the
 // render thread.
 IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest,
                        EffectiveConnectionTypeChangeNotfied) {
   base::HistogramTester histogram_tester;
   net::TestNetworkQualityEstimator estimator(
       nullptr, std::map<std::string, std::string>(), false, false, true, true,
@@ skipping 156 matching lines @@
       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