NetInfo: Slight update to the default network quality value

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 e4eec850d7fa659c225611fd3eaa1ad18a8b29a9..d0ca635a804fd63d673d6ad227f08e1c95969a05 100644
--- a/content/browser/net_info_browsertest.cc
+++ b/content/browser/net_info_browsertest.cc
@@ -2,6 +2,7 @@
 // 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>
 
@@ -164,7 +165,8 @@ IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest, TwoRenderViewsInOneProcess) {
 }
 
 // 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;
@@ -178,8 +180,18 @@ IN_PROC_BROWSER_TEST_F(NetInfoBrowserTest,
       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()"));
 }