Supporting command line argument to force field trials

chrome/browser/component_updater/pepper_flash_field_trial.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/component_updater/pepper_flash_field_trial.h"
 
 #include "base/command_line.h"
 #include "base/memory/ref_counted.h"
 #include "base/metrics/field_trial.h"
 #include "chrome/common/chrome_switches.h"
 
 namespace {
 
 const char* const kFieldTrialName = "PepperFlash";
 const char* const kDisableGroupName = "DisableByDefault";
 const char* const kEnableGroupName = "EnableByDefault";
+int g_disabled_group_number = -1;
 
 void ActivateFieldTrial() {
   // The field trial will expire on Jan 1st, 2014.
   scoped_refptr<base::FieldTrial> trial(
-      new base::FieldTrial(kFieldTrialName, 1000, kDisableGroupName,
-                           2014, 1, 1));
+      base::FieldTrialList::GetFieldTrialInstance(
+          kFieldTrialName, 1000, kDisableGroupName, &g_disabled_group_number,
+          2014, 1, 1));
 
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kPpapiFlashFieldTrial)) {
     std::string switch_value =
         command_line->GetSwitchValueASCII(switches::kPpapiFlashFieldTrial);
     if (switch_value == switches::kPpapiFlashFieldTrialEnableByDefault) {
       trial->AppendGroup(kEnableGroupName, 1000);
       return;
     } else if (switch_value ==
         switches::kPpapiFlashFieldTrialDisableByDefault) {
@@ skipping 15 matching lines @@
 // static
 bool PepperFlashFieldTrial::InEnableByDefaultGroup() {
   static bool activated = false;
   if (!activated) {
     ActivateFieldTrial();
     activated = true;
   }
 
   int group = base::FieldTrialList::FindValue(kFieldTrialName);
   return group != base::FieldTrial::kNotFinalized &&
-         group != base::FieldTrial::kDefaultGroupNumber;
+         group != g_disabled_group_number;
 }