NTP4: erase bubble promo UI

chrome/browser/resources/ntp4/new_tab.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. */
 
 html {
   /* It's necessary to put this here instead of in body in order to get the
      background-size of 100% to work properly */
   height: 100%;
   overflow: hidden;
 }
@@ skipping 114 matching lines @@
   margin: 0 9px;
 }
 
 #logo-img {
   display: inline-block;
   margin-top: 4px;
   overflow: hidden;
   position: relative;
 }
 
-#promo-bubble-anchor {
-  height: 1px;
-  left: 0;
-  position: absolute;
-  top: 4px;
-  visibility: hidden;
-  width: 32px;
-}
-
 .starting-up * {
   -webkit-transition: none !important;
 }
 
 /* Login Status. **************************************************************/
 
 #login-container {
   background: transparent none;
   border: none;
   box-shadow: none;
@@ skipping 208 matching lines @@
   padding: 0;
 }
 
 .other-sessions-promo-message:only-child {
   display: block;
 }
 
 .other-sessions-promo-message p {
   margin: 0;
 }