md-settings: Added settings for fingerprint unlock.

chrome/browser/chromeos/login/quick_unlock/quick_unlock_utils.cc

 // Copyright 2016 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/login/quick_unlock/quick_unlock_utils.h"
 
 #include "base/feature_list.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/common/chrome_features.h"
@@ skipping 18 matching lines @@
                              quick_unlock_whitelist_default.DeepCopy());
   registry->RegisterIntegerPref(
       prefs::kQuickUnlockTimeout,
       static_cast<int>(QuickUnlockPasswordConfirmationFrequency::DAY));
 
   // Preferences related the lock screen pin unlock.
   registry->RegisterIntegerPref(prefs::kPinUnlockMinimumLength, 4);
   // 0 indicates no maximum length for the pin.
   registry->RegisterIntegerPref(prefs::kPinUnlockMaximumLength, 0);
   registry->RegisterBooleanPref(prefs::kPinUnlockWeakPinsAllowed, true);
+
+  registry->RegisterBooleanPref(prefs::kEnableQuickUnlockFingerprint, false);
 }
 
 bool IsPinUnlockEnabled(PrefService* pref_service) {
   if (enable_for_testing_)
     return true;
 
   // Check if policy allows PIN.
   const base::ListValue* quick_unlock_whitelist =
       pref_service->GetList(prefs::kQuickUnlockModeWhitelist);
   base::StringValue all_value(kQuickUnlockWhitelistOptionAll);
   base::StringValue pin_value(kQuickUnlockWhitelistOptionPin);
   if (quick_unlock_whitelist->Find(all_value) ==
           quick_unlock_whitelist->end() &&
       quick_unlock_whitelist->Find(pin_value) ==
           quick_unlock_whitelist->end()) {
     return false;
   }
 
   // TODO(jdufault): Disable PIN for supervised users until we allow the owner
   // to set the PIN. See crbug.com/632797.
   user_manager::User* user = user_manager::UserManager::Get()->GetActiveUser();
   if (user && user->IsSupervised())
     return false;
 
   // Enable quick unlock only if the switch is present.
   return base::FeatureList::IsEnabled(features::kQuickUnlockPin);
 }
 
+bool IsFingerprintUnlockEnabled() {
+  // Enable fingerprint unlock only if the switch is present. The fingerprint
+  // settings are under the lock screen so we cannot set it up without
+  // kQuickUnlockPin enabled, so make sure that feature is turned on as well.
+  return base::FeatureList::IsEnabled(features::kQuickUnlockPin) &&

[Dan Beam, 2016/12/13 19:53:23]

can we rename the Pin version to just kQuickUnlock?

[sammiequon, 2016/12/13 23:33:33]

Should I add a TODO and bug or do you prefer to do it in this CL?

[jdufault, 2016/12/14 17:58:57]

That seems confusing; in the context of kQuickUnlock, kQuickUnlockFingerprint,
kQuickUnlockPattern (likely future addition), kQuickUnlockPin is significantly
more descriptive than kQuickUnlock.

If the name is too long, I would prefer kPinUnlock, kFingerprintUnlock, etc.

[Dan Beam, 2016/12/14 22:25:17]

it's not too long, it's confusing that the PIN version enables the fingerprint
version of unlock

[jdufault, 2016/12/14 23:32:56]

Yes, I agree. I think renaming only the flag/pref makes sense since it accounts
for more than just PIN. Though I'm not sure doing so is worthwhile, as the flag
is going to go away soonish; it is on by default for m57.

[sammiequon, 2017/01/10 22:33:27]

I removed the dependence on kQuickUnlockPin.

+         base::FeatureList::IsEnabled(features::kQuickUnlockFingerprint);
+}
+
 void EnableQuickUnlockForTesting() {
   enable_for_testing_ = true;
 }
 
 }  // namespace chromeos