[turbolizer] Focus on the svg after searching

After searching now we are focused on the svg, which allows using
the keyboard shortcuts after searching.

Bug: v8:7327
Change-Id: I57f5490ecb9858971aefae66b9808460108dc936
Notry: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1925147Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65084}

tools/turbolizer/src/graph-view.ts

@@ -492,6 +492,7 @@ export class GraphView extends PhaseView {
       this.updateGraphVisibility();
       searchBar.blur();
       this.viewSelection();
+      (document.getElementById("graph").childNodes[0] as HTMLElement).focus();
     }
     e.stopPropagation();
   }