[Smart Lock] Add a setting to require close proximity in order for unlocking to work.

chrome/browser/signin/easy_unlock_service.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_service.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
@@ skipping 190 matching lines @@
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 EasyUnlockService::~EasyUnlockService() {
 }
 
 // static
 void EasyUnlockService::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(
+      prefs::kEasyUnlockAllowed,
+      true,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterBooleanPref(
       prefs::kEasyUnlockEnabled,
       false,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterDictionaryPref(
       prefs::kEasyUnlockPairing,
       new base::DictionaryValue(),
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterBooleanPref(
-      prefs::kEasyUnlockAllowed,
-      true,
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+      prefs::kEasyUnlockProximityRequired,
+      false,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 }
 
 // static
 void EasyUnlockService::RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterDictionaryPref(prefs::kEasyUnlockHardlockState);
 }
 
 // static
 void EasyUnlockService::ResetLocalStateForUser(const std::string& user_id) {
   DCHECK(!user_id.empty());
@@ skipping 397 matching lines @@
 #endif
 
 void EasyUnlockService::PrepareForSuspend() {
   DisableAppIfLoaded();
   if (screenlock_state_handler_ && screenlock_state_handler_->IsActive()) {
     UpdateScreenlockState(
         EasyUnlockScreenlockStateHandler::STATE_BLUETOOTH_CONNECTING);
   }
 }