Remove unused CrosSetting kDeviceLoginScreenExtensions

Looks like this was introduced in
https://codereview.chromium.org/2111563002 and then renamed in
https://codereview.chromium.org/2711553002
but the introduced "plumbing"
(https://codereview.chromium.org/2144313002)
never actually used it. Instead, this is used through a pref.

Bug: 1151389
Test: compiles
Change-Id: Idd809a01c3e9ea0eb69bb61db44e32cd9ad2cc29
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2555017Reviewed-by: Alexander Hendrich <hendrich@chromium.org>
Commit-Queue: Alexander Hendrich <hendrich@chromium.org>
Commit-Queue: Pavol Marko <pmarko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830197}

chrome/browser/chromeos/settings/device_settings_provider.cc

@@ -82,7 +82,6 @@ const char* const kKnownSettings[] = {
     kDeviceDisplayResolution,
     kDeviceDockMacAddressSource,
     kDeviceHostnameTemplate,
-    kDeviceLoginScreenExtensions,
     kDeviceLoginScreenInputMethods,
     kDeviceLoginScreenLocales,
     kDeviceLoginScreenSystemInfoEnforced,
@@ -426,17 +425,6 @@ void DecodeLoginPolicies(const em::ChromeDeviceSettingsProto& policy,
                                base::Value(std::move(list)));
   }
 
-  if (policy.has_device_login_screen_extensions()) {
-    std::vector<base::Value> apps;
-    const em::DeviceLoginScreenExtensionsProto& proto(
-        policy.device_login_screen_extensions());
-    for (const auto& app : proto.device_login_screen_extensions()) {
-      apps.push_back(base::Value(app));
-    }
-    new_values_cache->SetValue(kDeviceLoginScreenExtensions,
-                               base::Value(std::move(apps)));
-  }
-
   if (policy.has_login_screen_locales()) {
     std::vector<base::Value> locales;
     const em::LoginScreenLocalesProto& login_screen_locales(

chromeos/settings/cros_settings_names.cc

@@ -327,12 +327,6 @@ const char kDeviceQuirksDownloadEnabled[] =
 const char kLoginVideoCaptureAllowedUrls[] =
     "cros.device.login_video_capture_allowed_urls";
 
-// A list pref storing the apps or extensions to install on the login page. It
-// is a list of strings, each string contains an extension ID and an update URL,
-// delimited by a semicolon. This preference is set by an admin policy.
-const char kDeviceLoginScreenExtensions[] =
-    "cros.device.login_screen_extensions";
-
 // A list pref specifying the locales allowed on the login screen. Currently
 // only the first value is used, as the single locale allowed on the login
 // screen.

chromeos/settings/cros_settings_names.h

@@ -190,9 +190,6 @@ extern const char kDeviceQuirksDownloadEnabled[];
 COMPONENT_EXPORT(CHROMEOS_SETTINGS)
 extern const char kLoginVideoCaptureAllowedUrls[];
 
-COMPONENT_EXPORT(CHROMEOS_SETTINGS)
-extern const char kDeviceLoginScreenExtensions[];
-
 COMPONENT_EXPORT(CHROMEOS_SETTINGS)
 extern const char kDeviceLoginScreenLocales[];
 COMPONENT_EXPORT(CHROMEOS_SETTINGS)