Identity API: Change WebAuthFlow to use <webview> instead of a normal browser pop-up.

chrome/browser/resources/identity_api_ui/identity_api_ui.css

Index: chrome/browser/resources/identity_api_ui/identity_api_ui.css
diff --git a/chrome/browser/resources/options/managed_user_set_passphrase.css b/chrome/browser/resources/identity_api_ui/identity_api_ui.css
similarity index 36%
copy from chrome/browser/resources/options/managed_user_set_passphrase.css
copy to chrome/browser/resources/identity_api_ui/identity_api_ui.css
index a92946c919b01a9651c9d3440a925479dc45d7f2..27db6cc66c66649d5273dc2200a49f87037a02e2 100644
--- a/chrome/browser/resources/options/managed_user_set_passphrase.css
+++ b/chrome/browser/resources/identity_api_ui/identity_api_ui.css
@@ -2,25 +2,35 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file. */
 
-#managed-user-set-passphrase-page {
-  background-color: white;
-  min-width: 400px;
+html {
+  margin: 0;
+  padding: 0;
 }
 
-#passphrase-missmatch,
-.managed-user-passphrase-container {
-  margin-top: 15px;
+body {
+  margin: 0;
+  padding: 0;
 }
 
-#managed-user-passphrase:invalid,
-#passphrase-confirm:invalid {
-  background-color: pink;
+.titlebar {
+  -webkit-app-region: drag;
+  background-color: white;
+  border-bottom: 1px solid #e5e5e5;
+  height: 26px;
+  white-space: nowrap;
+  width: 100%;
 }
 
-#passphrase-mismatch {
-  float: right;
+.titlebar-close-button {
+  -webkit-app-region: no-drag;
+  height: 14px;
+  margin: 6px;
+  position: absolute;
+  right: 0;
+  width: 14px;
 }
 
-html[dir=rtl] #passphrase-mismatch {
-  float: left;
+.content {
+  height: auto;
+  width: 100%;
 }