Remove the LowMemoryMargin field trial.

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

 // Copyright (c) 2013 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/chromeos/chrome_browser_main_chromeos.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/shell.h"
@@ skipping 766 matching lines @@
   // subsystems.
   automatic_reboot_manager_.reset();
 
   // Clean up dependency on CrosSettings and stop pending data fetches.
   KioskAppManager::Shutdown();
 
   ChromeBrowserMainPartsLinux::PostMainMessageLoopRun();
 }
 
 void ChromeBrowserMainPartsChromeos::SetupPlatformFieldTrials() {
-  SetupLowMemoryHeadroomFieldTrial();
   SetupZramFieldTrial();
 }
 
-void ChromeBrowserMainPartsChromeos::SetupLowMemoryHeadroomFieldTrial() {
-  chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
-  // Only enable this experiment on Canary and Dev, since it's possible
-  // that this will make the machine unstable.
-  // Note that to have this code execute in a developer build,
-  // then chrome::VersionInfo::CHANNEL_UNKNOWN needs to be added here.
-  if (channel == chrome::VersionInfo::CHANNEL_CANARY ||
-      channel == chrome::VersionInfo::CHANNEL_DEV) {
-    const base::FieldTrial::Probability kDivisor = 7;
-    // 1 in 7 probability of being in each group.  If the default value for the
-    // kernel matches one of the experiment groups, then they will have
-    // identical results.
-    const base::FieldTrial::Probability kEnableProbability = 1;
-    scoped_refptr<base::FieldTrial> trial =
-        base::FieldTrialList::FactoryGetFieldTrial(
-            "LowMemoryMargin", kDivisor, "default", 2012, 7, 30, NULL);
-    int disable = trial->AppendGroup("off", kEnableProbability);
-    int margin_0mb = trial->AppendGroup("0mb", kEnableProbability);
-    int margin_25mb = trial->AppendGroup("25mb", kEnableProbability);
-    int margin_50mb = trial->AppendGroup("50mb", kEnableProbability);
-    int margin_100mb = trial->AppendGroup("100mb", kEnableProbability);
-    int margin_200mb = trial->AppendGroup("200mb", kEnableProbability);
-    if (trial->group() == disable) {
-      LOG(WARNING) << "low_mem: Part of 'off' experiment";
-      LowMemoryObserver::SetLowMemoryMargin(-1);
-    } else if (trial->group() == margin_0mb) {
-      LOG(WARNING) << "low_mem: Part of '0MB' experiment";
-      LowMemoryObserver::SetLowMemoryMargin(0);
-    } else if (trial->group() == margin_25mb) {
-      LOG(WARNING) << "low_mem: Part of '25MB' experiment";
-      LowMemoryObserver::SetLowMemoryMargin(25);
-    } else if (trial->group() == margin_50mb) {
-      LOG(WARNING) << "low_mem: Part of '50MB' experiment";
-      LowMemoryObserver::SetLowMemoryMargin(50);
-    } else if (trial->group() == margin_100mb) {
-      LOG(WARNING) << "low_mem: Part of '100MB' experiment";
-      LowMemoryObserver::SetLowMemoryMargin(100);
-    } else if (trial->group() == margin_200mb) {
-      LOG(WARNING) << "low_mem: Part of '200MB' experiment";
-      LowMemoryObserver::SetLowMemoryMargin(200);
-    } else {
-      LOG(WARNING) << "low_mem: Part of 'default' experiment";
-    }
-  }
-}
-
-
 void ChromeBrowserMainPartsChromeos::SetupZramFieldTrial() {
   // The dice for this experiment have been thrown at boot.  The selected group
   // number is stored in a file.
   const base::FilePath kZramGroupPath("/home/chronos/.swap_exp_enrolled");
   std::string zram_file_content;
   // If the file does not exist, the experiment has not started.
   if (!file_util::ReadFileToString(kZramGroupPath, &zram_file_content))
     return;
   // The file contains a single significant character, possibly followed by
   // newline.  "x" means the user has opted out.  "0" through "8" are the valid
@@ skipping 25 matching lines @@
   trial->AppendGroup("4GB_RAM_4GB_swap", zram_group == '4' ? 1 : 0);
   trial->AppendGroup("4GB_RAM_6GB_swap", zram_group == '5' ? 1 : 0);
   trial->AppendGroup("snow_no_swap", zram_group == '6' ? 1 : 0);
   trial->AppendGroup("snow_1GB_swap", zram_group == '7' ? 1 : 0);
   trial->AppendGroup("snow_2GB_swap", zram_group == '8' ? 1 : 0);
   // This is necessary to start the experiment as a side effect.
   trial->group();
 }
 
 }  //  namespace chromeos