Merge branch 'ee-api-guard' into 'master'

Introduce EE::API::APIGuard::HelperMethods

See merge request gitlab-org/gitlab-ee!4378

ee/lib/ee/api/api_guard.rb

+module EE
+  module API
+    module APIGuard
+      module HelperMethods
+        extend ::Gitlab::Utils::Override
+
+        override :find_user_from_sources
+        def find_user_from_sources
+          find_user_from_access_token ||
+            find_user_from_job_token ||
+            find_user_from_warden
+        end
+      end
+    end
+  end
+end

lib/api/api_guard.rb

@@ -39,10 +39,11 @@ module API
 
     # Helper Methods for Grape Endpoint
     module HelperMethods
+      prepend EE::API::APIGuard::HelperMethods
       include Gitlab::Auth::UserAuthFinders
 
       def find_current_user!
-        user = find_user_from_access_token || find_user_from_job_token || find_user_from_warden
+        user = find_user_from_sources
         return unless user
 
         forbidden!('User is blocked') unless Gitlab::UserAccess.new(user).allowed? && user.can?(:access_api)
@@ -50,6 +51,10 @@ module API
         user
       end
 
+      def find_user_from_sources
+        find_user_from_access_token || find_user_from_warden
+      end
+
       private
 
       # An array of scopes that were registered (using `allow_access_with_scope`)