Changed SystemFeaturesDisableList to enum list

This pref is going to be checked in multiple places; extensions
management, settings button, web apps, so I found it better to change
it to a list of enums instead of a list of strings.

Bug: 1061859
Change-Id: Ib0bde940c0248f2508271ac0cbfc915ee5e3ca49
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2124752
Commit-Queue: Aya Elsayed <ayaelattar@google.com>
Reviewed-by: Sergey Poromov <poromov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#754511}

chrome/browser/chromeos/policy/system_features_disable_list_policy_handler.cc

@@ -27,8 +27,23 @@ void SystemFeaturesDisableListPolicyHandler::ApplyList(
     base::Value filtered_list,
     PrefValueMap* prefs) {
   DCHECK(filtered_list.is_list());
+  base::Value enums_list(base::Value::Type::LIST);
+  for (const auto& element : filtered_list.GetList()) {
+    enums_list.Append(ConvertToEnum(element.GetString()));
+  }
   prefs->SetValue(policy_prefs::kSystemFeaturesDisableList,
-                  std::move(filtered_list));
+                  std::move(enums_list));
+}
+
+SystemFeature SystemFeaturesDisableListPolicyHandler::ConvertToEnum(
+    const std::string& system_feature) {
+  if (system_feature == "camera")
+    return SystemFeature::CAMERA;
+  if (system_feature == "settings")
+    return SystemFeature::SETTINGS;
+
+  NOTREACHED() << "Unsupported system feature: " << system_feature;
+  return LAST_SYSTEM_FEATURE;
 }
 
 }  // namespace policy

chrome/browser/chromeos/policy/system_features_disable_list_policy_handler.h

@@ -15,6 +15,15 @@ class PrefRegistrySimple;
 
 namespace policy {
 
+// A system feature that can be disabled by SystemFeaturesDisableList policy.
+enum SystemFeature {
+  CAMERA = 0,  // The camera chrome app on Chrome OS.
+  SETTINGS,    // The settings feature on Chrome OS. It includes also Chrome
+               // settings.
+
+  LAST_SYSTEM_FEATURE
+};
+
 class SystemFeaturesDisableListPolicyHandler
     : public policy::ListPolicyHandler {
  public:
@@ -26,6 +35,9 @@ class SystemFeaturesDisableListPolicyHandler
  protected:
   // ListPolicyHandler:
   void ApplyList(base::Value filtered_list, PrefValueMap* prefs) override;
+
+ private:
+  SystemFeature ConvertToEnum(const std::string& system_feature);
 };
 
 }  // namespace policy