ChromeOS OOBE: Fix keyboard focusing of OOBE buttons.

chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css

Index: chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css
diff --git a/chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css b/chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css
index 19b9339599909af17aa779a71fe77a7a4829110a..d825a6176ab1a18c300ca0573be23ed692b19e77 100644
--- a/chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css
+++ b/chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css
@@ -2,19 +2,40 @@
    Use of this source code is governed by a BSD-style license that can be
    found in the LICENSE file. */
 :host {
-  border-color: rgba(0, 0, 0, 0.2);
-  border-radius: 2px;
-  border-style: solid;
-  border-width: 1px;
   color: #5a5a5a;
-  height: 28px;
+  height: 32px; /* = 28 + 2 * 2px keyboad-focus border */
   max-width: 300px;
   min-width: 120px;
 }
 
-#container {
+#button {
+  --paper-button-flat-keyboard-focus: {
+    border-color: rgba(66, 133, 244, 0.4); /* #4284f4 */
+    border-radius: 2px;
+    border-style: solid;
+    border-width: 2px;
+  };
   height: 100%;
   margin: 0;
+  padding: 0;
+  width: 100%;
+}
+
+#button:not([focused]) {
+  border-color: transparent;
+  border-radius: 2px;
+  border-style: solid;
+  border-width: 2px;
+}
+
+#container {
+  border-color: rgba(0, 0, 0, 0.2);
+  border-radius: 2px;
+  border-style: solid;
+  border-width: 1px;
+}
+
+#subcontainer {
   padding: 0 16px 0 16px;
 }