Merge 54411 - Reduce magnitude of non-default group probabilities for 2 A/B t...

chrome/browser/browser_main.cc

 // Copyright (c) 2010 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 "chrome/browser/browser_main.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 160 matching lines @@
   PostEarlyInitialization();
 }
 
 // This is an A/B test for the maximum number of persistent connections per
 // host. Currently Chrome, Firefox, and IE8 have this value set at 6. Safari
 // uses 4, and Fasterfox (a plugin for Firefox that supposedly configures it to
 // run faster) uses 8. We would like to see how much of an effect this value has
 // on browsing. Too large a value might cause us to run into SYN flood detection
 // mechanisms.
 void BrowserMainParts::ConnectionFieldTrial() {
-  const FieldTrial::Probability kConnectDivisor = 100;
-  const FieldTrial::Probability kConnectProbability = 20;  // 20% probability
+  const FieldTrial::Probability kConnectDivisor = 1000;
+  const FieldTrial::Probability kConnectProbability = 20;  // 2% probability
 
   scoped_refptr<FieldTrial> connect_trial =
       new FieldTrial("ConnCountImpact", kConnectDivisor);
 
   const int connect_5 = connect_trial->AppendGroup("_conn_count_5",
                                                    kConnectProbability);
   const int connect_7 = connect_trial->AppendGroup("_conn_count_7",
                                                    kConnectProbability);
   const int connect_8 = connect_trial->AppendGroup("_conn_count_8",
                                                    kConnectProbability);
@@ skipping 22 matching lines @@
     NOTREACHED();
   }
 }
 
 // A/B test for determining a value for unused socket timeout. Currently the
 // timeout defaults to 10 seconds. Having this value set too low won't allow us
 // to take advantage of idle sockets. Setting it to too high could possibly
 // result in more ERR_CONNECT_RESETs, requiring one RTT to receive the RST
 // packet and possibly another RTT to re-establish the connection.
 void BrowserMainParts::SocketTimeoutFieldTrial() {
-  const FieldTrial::Probability kIdleSocketTimeoutDivisor = 100;
-  // 25% probability
+  const FieldTrial::Probability kIdleSocketTimeoutDivisor = 1000;
+  // 2.5% probability
   const FieldTrial::Probability kSocketTimeoutProbability = 25;
 
   scoped_refptr<FieldTrial> socket_timeout_trial =
       new FieldTrial("IdleSktToImpact", kIdleSocketTimeoutDivisor);
 
   const int socket_timeout_5 =
       socket_timeout_trial->AppendGroup("_idle_timeout_5",
                                         kSocketTimeoutProbability);
   const int socket_timeout_20 =
       socket_timeout_trial->AppendGroup("_idle_timeout_20",
@@ skipping 1077 matching lines @@
 
   metrics->Stop();
 
   // browser_shutdown takes care of deleting browser_process, so we need to
   // release it.
   ignore_result(browser_process.release());
   browser_shutdown::Shutdown();
 
   return result_code;
 }