Control easy unlock by a field trial.

chrome/browser/signin/easy_unlock.cc

 // Copyright 2014 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/signin/easy_unlock.h"
 
+#include "base/command_line.h"
+#include "base/metrics/field_trial.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/extensions/application_launch.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "extensions/browser/extension_system.h"
 
 namespace easy_unlock {
 
 void RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(
       prefs::kEasyUnlockEnabled,
@@ skipping 12 matching lines @@
 void LaunchEasyUnlockSetup(Profile* profile) {
   ExtensionService* service =
       extensions::ExtensionSystem::Get(profile)->extension_service();
   const extensions::Extension* extension =
       service->GetExtensionById(extension_misc::kEasyUnlockAppId, false);
 
   OpenApplication(AppLaunchParams(
       profile, extension, extensions::LAUNCH_CONTAINER_WINDOW, NEW_WINDOW));
 }
 
+bool IsEnabled() {
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableEasyUnlock)) {

[Alexei Svitkine (slow), 2014/07/22 18:18:41]

Please follow the pattern at the bottom of go/finch-and-flags.

[xiyuan, 2014/07/22 20:00:23]

Done.

+    return true;
+  }
+
+  const char kFieldTrialName[] = "EasyUnlock";
+  const char kEnable[] = "Enable";
+  return base::FieldTrialList::FindFullName(kFieldTrialName) == kEnable;
+}
+
 }  // namespace easy_unlock