DevTools: Don't use event.keyIdentifier

It is deprecated.

Bug: 633619
Change-Id: I24e33f31bf84fcd53ab5c8878e83ae6be872ff16
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1504754
Reviewed-by: Erik Luo <luoe@chromium.org>
Commit-Queue: Joel Einbinder <einbinder@chromium.org>
Cr-Commit-Position: refs/heads/master@{#640589}

third_party/blink/renderer/devtools/front_end/accessibility/ARIAAttributesView.js

@@ -177,7 +177,7 @@ Accessibility.ARIAAttributesTreeElement = class extends UI.TreeElement {
       return;
     }
 
-    if (event.keyCode === UI.KeyboardShortcut.Keys.Esc.code || event.keyIdentifier === 'U+001B') {
+    if (isEscKey(event)) {
       this._editingCancelled();
       event.consume();
       return;