[Password Manager] Add link to remotely manage passowrds on desktop

ui/webui/resources/css/overlay.css

 /* Copyright (c) 2012 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. */
 
 /* The shield that overlays the background. */
 .overlay {
   -webkit-box-align: center;
   -webkit-box-orient: vertical;
   -webkit-box-pack: center;
   /* TODO(dbeam): remove perspective when http://crbug.com/374970 is fixed. */
@@ skipping 132 matching lines @@
 
 .overlay .page .button-strip > button {
   -webkit-margin-start: 10px;
   display: block;
 }
 
 .overlay .page .button-strip > .default-button:not(:focus) {
   border-color: rgba(0, 0, 0, 0.5);
 }
 
+.overlay .page .spacer-div {
+  -webkit-box-flex: 1;
+}
+
 /* On OSX 10.7, hidden scrollbars may prevent the user from realizing that the
  * overlay contains scrollable content. To resolve this, style the scrollbars on
  * OSX so they are always visible. See http://crbug.com/123010. */
 <if expr="is_macosx or is_ios">
 .overlay .page .content-area::-webkit-scrollbar {
   -webkit-appearance: none;
   width: 11px;
 }
 
 .overlay .page .content-area::-webkit-scrollbar-thumb {
@@ skipping 25 matching lines @@
 #overlay-container-1 {
   z-index: 11;
 }
 #overlay-container-2 {
   z-index: 12;
 }
 
 .transparent {
   opacity: 0;
 }