Fix overflow behavior for Interest Groups

This has been fixed here crrev.com/c/3436688 but through some
refactorings the CSS no longer applies to the correct widget.

Fixed: 402806164
Change-Id: I181a8eff68532f024a1eb99f40b48144a9a10c0e
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6396059
Auto-Submit: Yang Guo <[email protected]>
Commit-Queue: Yang Guo <[email protected]>
Reviewed-by: Kim-Anh Tran <[email protected]>
Commit-Queue: Kim-Anh Tran <[email protected]>

Author: hashseed

front_end/panels/application/InterestGroupStorageView.ts

@@ -87,9 +87,9 @@ export class InterestGroupStorageView extends UI.SplitWidget.SplitWidget {
 
   override wasShown(): void {
     super.wasShown();
-    const sbw = this.sidebarWidget();
-    if (sbw) {
-      sbw.registerRequiredCSS(interestGroupStorageViewStyles);
+    const mainWidget = this.mainWidget();
+    if (mainWidget) {
+      mainWidget.registerRequiredCSS(interestGroupStorageViewStyles);
     }
   }