Rename async getters in CSSModel.ts

Bug: 1301903
Change-Id: I9ac4f5cef2d6e4d6ee5589f0163022a255dec943
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/3497015
Reviewed-by: Tim Van der Lippe <[email protected]>
Reviewed-by: Changhao Han <[email protected]>
Commit-Queue: Johan Bay <[email protected]>
diff --git a/front_end/panels/elements/ClassesPaneWidget.ts b/front_end/panels/elements/ClassesPaneWidget.ts
index 70d4519..5d99576 100644
--- a/front_end/panels/elements/ClassesPaneWidget.ts
+++ b/front_end/panels/elements/ClassesPaneWidget.ts
@@ -313,7 +313,7 @@
       if (stylesheet.frameId !== this.selectedFrameId) {
         continue;
       }
-      const cssPromise = cssModel.classNamesPromise(stylesheet.id).then(classes => {
+      const cssPromise = cssModel.getClassNames(stylesheet.id).then(classes => {
         for (const className of classes) {
           completions.add(className);
         }