Instantiate ImageFile for diff-files in Diff

app/assets/javascripts/commit/file.js

@@ -3,7 +3,7 @@
   this.CommitFile = (function() {
     function CommitFile(file) {
       if ($('.image', file).length) {
-        new ImageFile(file);
+        new gl.ImageFile(file);
       }
     }
 

app/assets/javascripts/commit/image_file.js

@@ -1,6 +1,6 @@
 /* eslint-disable func-names, space-before-function-paren, wrap-iife, no-var, no-use-before-define, prefer-arrow-callback, no-else-return, consistent-return, prefer-template, quotes, one-var, one-var-declaration-per-line, no-unused-vars, no-return-assign, comma-dangle, quote-props, no-unused-expressions, no-sequences, object-shorthand, padded-blocks, max-len */
 (function() {
-  this.ImageFile = (function() {
+  gl.ImageFile = (function() {
     var prepareFrames;
 
     // Width where images must fits in, for 2-up this gets divided by 2

app/assets/javascripts/diff.js.es6

@@ -5,8 +5,11 @@
 
   class Diff {
     constructor() {
-      $('.files .diff-file').singleFileDiff();
-      $('.files .diff-file').filesCommentButton();
+      const $diffFile = $('.files .diff-file');
+      $diffFile.singleFileDiff();
+      $diffFile.filesCommentButton();
+
+      $diffFile.each((index, file) => new gl.ImageFile(file));
 
       if (this.diffViewType() === 'parallel') {
         $('.content-wrapper .container-fluid').removeClass('container-limited');

changelogs/unreleased/24949-view-2-up-swipe-onion-skin-controls-for-merge-request-diff-containing-an-image.yml

@@ -0,0 +1,4 @@
+---
+title: Add image controls to MR diffs
+merge_request: 7919
+author: