Merge branch 'ee-parallel-diff-view-ce' into 'master'

CE backport of ee-parallel-diff-view

See merge request gitlab-org/gitlab-ce!25734

app/assets/javascripts/diffs/components/parallel_diff_view.vue

 <script>
 import { mapGetters } from 'vuex';
+import draftCommentsMixin from 'ee_else_ce/diffs/mixins/draft_comments';
 import parallelDiffTableRow from './parallel_diff_table_row.vue';
 import parallelDiffCommentRow from './parallel_diff_comment_row.vue';
 
@@ -7,7 +8,10 @@ export default {
   components: {
     parallelDiffTableRow,
     parallelDiffCommentRow,
+    ParallelDraftCommentRow: () =>
+      import('ee_component/batch_comments/components/parallel_draft_comment_row.vue'),
   },
+  mixins: [draftCommentsMixin],
   props: {
     diffFile: {
       type: Object,
@@ -56,6 +60,12 @@ export default {
             :line-index="index"
             :help-page-path="helpPagePath"
           />
+          <parallel-draft-comment-row
+            v-if="shouldRenderParallelDraftRow(diffFile.file_hash, line)"
+            :key="`drafts-${index}`"
+            :line="line"
+            :diff-file-content-sha="diffFile.file_hash"
+          />
         </template>
       </tbody>
     </table>

app/assets/javascripts/diffs/mixins/draft_comments.js

 export default {
   computed: {
     shouldRenderDraftRow: () => () => false,
+    shouldRenderParallelDraftRow: () => () => false,
     draftForLine: () => () => ({}),
   },
 };