Delete long-expired GlobalSdch field trial.

chrome/browser/chrome_browser_main.cc

 // Copyright (c) 2012 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/chrome_browser_main.h"
 
 #if defined(TOOLKIT_GTK)
 #include <gtk/gtk.h>
 #endif
 
@@ skipping 1384 matching lines @@
   GoogleSearchCounter::RegisterForNotifications();
 
   // Disable SDCH filtering if switches::kEnableSdch is 0.
   int sdch_enabled = 1;
   if (parsed_command_line().HasSwitch(switches::kEnableSdch)) {
     base::StringToInt(parsed_command_line().GetSwitchValueASCII(
         switches::kEnableSdch), &sdch_enabled);
     if (!sdch_enabled)
       net::SdchManager::EnableSdchSupport(false);
   }
-  if (sdch_enabled) {
-    // Perform A/B test to measure global impact of SDCH support.
-    // Set up a field trial to see what disabling SDCH does to latency of page
-    // layout globally.
-    base::FieldTrial::Probability kSDCH_DIVISOR = 1000;
-    base::FieldTrial::Probability kSDCH_DISABLE_PROBABILITY = 1;  // 0.1% prob.
-    // After March 31, 2012 builds, it will always be in default group.
-    int sdch_enabled_group = -1;
-    scoped_refptr<base::FieldTrial> sdch_trial(
-        base::FieldTrialList::FactoryGetFieldTrial(
-            "GlobalSdch", kSDCH_DIVISOR, "global_enable_sdch", 2012, 3, 31,
-            &sdch_enabled_group));
-
-    sdch_trial->AppendGroup("global_disable_sdch",
-                            kSDCH_DISABLE_PROBABILITY);
-    if (sdch_enabled_group != sdch_trial->group())
-      net::SdchManager::EnableSdchSupport(false);
-  }
 
   if (parsed_command_line().HasSwitch(switches::kEnableWatchdog))
     InstallJankometer(parsed_command_line());
 
 #if defined(OS_WIN) && !defined(GOOGLE_CHROME_BUILD)
   if (parsed_command_line().HasSwitch(switches::kDebugPrint)) {
     base::FilePath path =
         parsed_command_line().GetSwitchValuePath(switches::kDebugPrint);
     printing::PrintedDocument::set_debug_dump_path(path);
   }
@@ skipping 359 matching lines @@
     if (base::win::GetVersion() <= base::win::VERSION_XP)
       uma_name += "_XP";
 
     uma_name += "_PreRead_";
     uma_name += pre_read_percentage;
     AddPreReadHistogramTime(uma_name.c_str(), time);
   }
 #endif
 #endif
 }