Remove unnecessary window exports.

app/assets/javascripts/merge_conflict_data_provider.js.es6

 const HEAD_HEADER_TEXT    = 'HEAD//our changes';
 const ORIGIN_HEADER_TEXT  = 'origin//their changes';
-
 const HEAD_BUTTON_TITLE   = 'Use ours';
 const ORIGIN_BUTTON_TITLE = 'Use theirs';
 
-window.MergeConflictDataProvider = class MergeConflictDataProvider {
+
+class MergeConflictDataProvider {
 
   getInitialData() {
     const diffViewType = $.cookie('diff_view');

app/assets/javascripts/merge_conflict_resolver.js.es6

 //= require lib/vue
 
-window.MergeConflictResolver = class MergeConflictResolver {
+class MergeConflictResolver {
 
   constructor() {
     this.dataProvider = new MergeConflictDataProvider()