Mark ECT as ambiguous if there is a change in the connection type.

components/metrics/net/network_metrics_provider_unittest.cc

 // Copyright 2017 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 "components/metrics/net/network_metrics_provider.h"
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
@@ skipping 93 matching lines @@
             system_profile.network().effective_connection_type());
 
   // Getting the system profile again should return the actual effective
   // connection type since the effective connection type did not change during
   // the lifetime of the log.
   network_metrics_provider.ProvideSystemProfileMetrics(&system_profile);
   EXPECT_EQ(SystemProfileProto::Network::EFFECTIVE_CONNECTION_TYPE_SLOW_2G,
             system_profile.network().effective_connection_type());
 }
 
+// Verifies that the effective connection type is set to AMBIGUOUS when there is
+// a change in the connection type.
+TEST(NetworkMetricsProviderTest, ECTAmbiguousOnConnectionTypeChange) {
+  base::MessageLoop loop(base::MessageLoop::TYPE_IO);
+
+#if defined(OS_CHROMEOS)
+  chromeos::DBusThreadManager::Initialize();
+  chromeos::NetworkHandler::Initialize();
+#endif  // OS_CHROMEOS

[Alexei Svitkine (slow), 2017/01/27 22:01:40]

Nit: Can this goop go into the test harness ctor?

[tbansal1, 2017/01/29 07:12:27]

Done.

+
+  net::TestNetworkQualityEstimator estimator;
+  std::unique_ptr<NetworkMetricsProvider::NetworkQualityEstimatorProvider>
+      estimator_provider(base::WrapUnique(
+          new TestNetworkQualityEstimatorProvider(&estimator)));
+  SystemProfileProto system_profile;
+  NetworkMetricsProvider network_metrics_provider(
+      std::move(estimator_provider), base::ThreadTaskRunnerHandle::Get().get());
+
+  EXPECT_EQ(net::EFFECTIVE_CONNECTION_TYPE_UNKNOWN,
+            network_metrics_provider.effective_connection_type_);
+  EXPECT_FALSE(
+      network_metrics_provider.effective_connection_type_is_ambiguous_);
+
+  network_metrics_provider.OnConnectionTypeChanged(
+      net::NetworkChangeNotifier::CONNECTION_2G);
+  EXPECT_TRUE(network_metrics_provider.effective_connection_type_is_ambiguous_);
+  network_metrics_provider.ProvideSystemProfileMetrics(&system_profile);
+  EXPECT_EQ(SystemProfileProto::Network::EFFECTIVE_CONNECTION_TYPE_AMBIGUOUS,
+            system_profile.network().effective_connection_type());
+}
+
 }  // namespace metrics