Replace the WAS_INSTALLED_BY_CUSTODIAN creation flag with a pref

chrome/browser/extensions/extension_sync_data.h

Index: chrome/browser/extensions/extension_sync_data.h
diff --git a/chrome/browser/extensions/extension_sync_data.h b/chrome/browser/extensions/extension_sync_data.h
index d03362697709cd89d215c4b931dd9fd65051846b..67f56c6cc3e812886977b6dff10de18831a65c20 100644
--- a/chrome/browser/extensions/extension_sync_data.h
+++ b/chrome/browser/extensions/extension_sync_data.h
@@ -53,7 +53,8 @@ class ExtensionSyncData {
                     int disable_reasons,
                     bool incognito_enabled,
                     bool remote_install,
-                    OptionalBoolean all_urls_enabled);
+                    OptionalBoolean all_urls_enabled,
+                    bool installed_by_custodian);
   // App constructor.
   ExtensionSyncData(const Extension& extension,
                     bool enabled,
@@ -61,6 +62,7 @@ class ExtensionSyncData {
                     bool incognito_enabled,
                     bool remote_install,
                     OptionalBoolean all_urls_enabled,
+                    bool installed_by_custodian,
                     const syncer::StringOrdinal& app_launch_ordinal,
                     const syncer::StringOrdinal& page_ordinal,
                     extensions::LaunchType launch_type);