Fix Project#repository_and_lfs_size after removing repository_size method

app/models/project.rb

@@ -1507,7 +1507,7 @@ class Project < ActiveRecord::Base
   end
 
   def repository_and_lfs_size
-    repository_size + lfs_objects.sum(:size).to_i.to_mb
+    statistics.storage_size + statistics.lfs_objects_size
   end
 
   def above_size_limit?

spec/lib/gitlab/repository_size_error_spec.rb

 require 'spec_helper'
 
 describe Gitlab::RepositorySizeError, lib: true do
-  let(:project) { create(:empty_project, repository_size: 15) }
+  let(:project) do
+    create(:empty_project, statistics: build(:project_statistics, repository_size: 15))
+  end
+
   let(:message) { Gitlab::RepositorySizeError.new(project) }
   let(:base_message) { 'because this repository has exceeded its size limit of 10 MB by 5 MB' }
 

spec/models/project_spec.rb

@@ -588,6 +588,11 @@ describe Project, models: true do
     end
 
     describe '#above_size_limit?' do
+      let(:project) do
+        create(:empty_project,
+               statistics: build(:project_statistics))
+      end
+
       it 'returns true when above the limit' do
         allow(project).to receive(:repository_and_lfs_size).and_return(100)