cros: Selectively fork login assets.

ui/login/account_picker/md_user_pod_template.css

Index: ui/login/account_picker/md_user_pod_template.css
diff --git a/ui/login/account_picker/md_user_pod_template.css b/ui/login/account_picker/md_user_pod_template.css
new file mode 100644
index 0000000000000000000000000000000000000000..fdc9f0f5640fbdd9d862e600046218bad7c0defe
--- /dev/null
+++ b/ui/login/account_picker/md_user_pod_template.css
@@ -0,0 +1,20 @@
+/* Copyright 2016 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * This is the stylesheet imported into the style module in
+ * user_pod_template.html.
+ */
+
+.action-box-remove-user-warning .remove-warning-button {
+  --paper-button: {
+    background: var(--google-red-700);
+    color: white;
+    font-weight: 600;
+    @apply(--layout-vertical);
+  };
+  --paper-button-flat-keyboard-focus: {
+    background: rgb(173, 50, 36);
+  };
+  @apply(--action-button);
+}