Fix regression with Objective-C api whitespace formatting (#670)

Resolves: rdar://109681482

Author: mportiz08

src/components/DocumentationTopic/PrimaryContent/DeclarationSource.vue

@@ -196,7 +196,7 @@ export default {
   async mounted() {
     if (this.language === Language.objectiveC.key.api) {
       await this.$nextTick();
-      indentDeclaration(this.$refs.code, this.language);
+      indentDeclaration(this.$refs.code.$el, this.language);
     }
     if (hasMultipleLines(this.$refs.declarationGroup)) this.hasMultipleLines = true;
   },

tests/unit/components/DocumentationTopic/PrimaryContent/DeclarationSource.spec.js

@@ -109,7 +109,7 @@ describe('DeclarationSource', () => {
     await flushPromises();
     expect(indentDeclaration).toHaveBeenCalledTimes(1);
     expect(indentDeclaration)
-      .toHaveBeenCalledWith(wrapper.find({ ref: 'code' }).vm, Language.objectiveC.key.api);
+      .toHaveBeenCalledWith(wrapper.find({ ref: 'code' }).vm.$el, Language.objectiveC.key.api);
     expect(callStack).toEqual(['indentDeclaration', 'hasMultipleLines']);
   });
 });