Ash Display: Add IsManaged() function to PrivacyScreenController.

BUG=1040648

Change-Id: I58630f7fbffc0132745b0b14f20816a3980a4a97
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2079800Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Gil Dekel <gildekel@chromium.org>
Commit-Queue: Tim Song <tengs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#745369}

ash/display/privacy_screen_controller.cc

@@ -37,6 +37,11 @@ bool PrivacyScreenController::IsSupported() const {
       ->IsPrivacyScreenSupportedOnInternalDisplay();
 }
 
+bool PrivacyScreenController::IsManaged() const {
+  return active_user_pref_service_->IsManagedPreference(
+      prefs::kDisplayPrivacyScreenEnabled);
+}
+
 bool PrivacyScreenController::GetEnabled() const {
   return active_user_pref_service_ && active_user_pref_service_->GetBoolean(
                                           prefs::kDisplayPrivacyScreenEnabled);

ash/display/privacy_screen_controller.h

@@ -42,6 +42,8 @@ class ASH_EXPORT PrivacyScreenController
 
   // Whether or not the privacy screen feature is supported by the device.
   bool IsSupported() const;
+  // Whether or not the privacy screen feature is enforced by policy.
+  bool IsManaged() const;
   // Get the PrivacyScreen settings stored in the current active user prefs.
   bool GetEnabled() const;
   // Set the desired PrivacyScreen settings in the current active user prefs.