Revert of Remove support for Alt-Svc/Alternate Protocol Probability

chrome/browser/io_thread_unittest.cc

Index: chrome/browser/io_thread_unittest.cc
diff --git a/chrome/browser/io_thread_unittest.cc b/chrome/browser/io_thread_unittest.cc
index abf93c2ea2326e5b81e962633a9893714d766bd0..5383823c5ac12a329bc5b08ecce6f00f3ffc6900 100644
--- a/chrome/browser/io_thread_unittest.cc
+++ b/chrome/browser/io_thread_unittest.cc
@@ -235,6 +235,7 @@
   EXPECT_FALSE(params.disable_quic_on_timeout_with_open_streams);
   EXPECT_TRUE(params.enable_quic_for_proxies);
   EXPECT_EQ(1350u, params.quic_max_packet_length);
+  EXPECT_EQ(1.0, params.alternative_service_probability_threshold);
   EXPECT_EQ(default_params.quic_supported_versions,
             params.quic_supported_versions);
   EXPECT_EQ(net::QuicTagVector(), params.quic_connection_options);
@@ -603,6 +604,47 @@
   EXPECT_TRUE(params.quic_delay_tcp_race);
 }
 
+TEST_F(IOThreadTest, AlternativeServiceProbabilityThresholdFromFlag) {
+  command_line_.AppendSwitchASCII("alternative-service-probability-threshold",
+                                  "0.5");
+
+  ConfigureQuicGlobals();
+  net::HttpNetworkSession::Params params;
+  InitializeNetworkSessionParams(&params);
+  EXPECT_EQ(.5, params.alternative_service_probability_threshold);
+}
+
+TEST_F(IOThreadTest, AlternativeServiceProbabilityThresholdFromEnableQuicFlag) {
+  command_line_.AppendSwitch("enable-quic");
+
+  ConfigureQuicGlobals();
+  net::HttpNetworkSession::Params params;
+  InitializeNetworkSessionParams(&params);
+  EXPECT_EQ(0, params.alternative_service_probability_threshold);
+}
+
+// TODO(bnc): Remove when new parameter name rolls out and server configuration
+// is changed.
+TEST_F(IOThreadTest, AlternativeServiceProbabilityThresholdFromOldParams) {
+  field_trial_group_ = "Enabled";
+  field_trial_params_["alternate_protocol_probability_threshold"] = ".5";
+
+  ConfigureQuicGlobals();
+  net::HttpNetworkSession::Params params;
+  InitializeNetworkSessionParams(&params);
+  EXPECT_EQ(.5, params.alternative_service_probability_threshold);
+}
+
+TEST_F(IOThreadTest, AlternativeServiceProbabilityThresholdFromParams) {
+  field_trial_group_ = "Enabled";
+  field_trial_params_["alternative_service_probability_threshold"] = ".5";
+
+  ConfigureQuicGlobals();
+  net::HttpNetworkSession::Params params;
+  InitializeNetworkSessionParams(&params);
+  EXPECT_EQ(.5, params.alternative_service_probability_threshold);
+}
+
 TEST_F(IOThreadTest, QuicWhitelistFromCommandLinet) {
   command_line_.AppendSwitch("enable-quic");
   command_line_.AppendSwitchASCII("quic-host-whitelist",