DevTools: Focus the add workspace button by default

Bug: 759491
Change-Id: I4dc8f3a1971964a2b301c4ca3c4e438e9d84ee27
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1513208
Reviewed-by: Dmitry Gozman <[email protected]>
Commit-Queue: Joel Einbinder <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#640176}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: adc0e9be5563cee7dc975f4d3ae866098431fed7
diff --git a/front_end/persistence/WorkspaceSettingsTab.js b/front_end/persistence/WorkspaceSettingsTab.js
index 7f9c03d..36a865b 100644
--- a/front_end/persistence/WorkspaceSettingsTab.js
+++ b/front_end/persistence/WorkspaceSettingsTab.js
@@ -29,8 +29,9 @@
 
     this._fileSystemsListContainer = this.containerElement.createChild('div', '');
 
-    this.containerElement.appendChild(
-        UI.createTextButton(Common.UIString('Add folder\u2026'), this._addFileSystemClicked.bind(this)));
+    const addButton = UI.createTextButton(ls`Add folder\u2026`, this._addFileSystemClicked.bind(this));
+    this.containerElement.appendChild(addButton);
+    this.setDefaultFocusedElement(addButton);
 
     /** @type {!Map<string, !Element>} */
     this._elementByPath = new Map();