Make all quota-exceeding messages in the storage API explain what the failure

chrome/common/extensions/docs/server2/static/css/site.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.
  */
 
 .hidden {
   display: none;
 }
 
 body {
@@ skipping 348 matching lines @@
   margin: 1.3em 1em 0 0;
   padding: 0;
 }
 
 #toc {
   background-color: #F5F5F5;
   float: right;
   margin: 5px 0px 5px 20px;
   padding: 5px;
   width: 250px;
+  word-break: break-all;
 }
 
 #toc * {
   padding: 0;
   list-style: none;
   font-weight: 600;
 }
 
 #toc h2 {
   font-weight: bold;
@@ skipping 50 matching lines @@
 
 td.gsc-input {
   padding: 0 0;
 }
 
 div.gsc-input-box {
   height: 30px;
   width: 250px;
   float: right;
 }