downloads: break downloads.js into more classes/files.

chrome/browser/resources/downloads/downloads.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. */
 
 <include src="../search_header.css">
 
 #downloads-summary-text {
   font-weight: bold;
 }
 
@@ skipping 66 matching lines @@
 html[dir=rtl] .download.otr > .safe,
 html[dir=rtl] .download.otr > .show-dangerous {
   background-position: left bottom;
 }
 
 .download.otr > .safe:hover,
 .download.otr > .show-dangerous:hover {
   opacity: 1;
 }
 
-.malware-description {
+.description.malware {
   color: rgb(196, 42, 23);
 }
 
 .progress {
   height: 48px;
   left: 0;
   position: absolute;
   top: -6px;
   width: 48px;
 }
 
 html[dir=rtl] .progress {
   left: auto;
   right: 0;
 }
 
 .progress.background {
   background: url(chrome://theme/IDR_DOWNLOAD_PROGRESS_BACKGROUND_32);
   background-size: 48px;
 }
 
 .name,
 .src-url,
-.controls a {
+.controls a,
+.description {
   -webkit-padding-end: 4px;
   -webkit-padding-start: 4px;
 }
 
 .name {
   -webkit-padding-end: 16px;
   display: inline-block;
   max-width: 450px;
   word-break: break-all;
 }
@@ skipping 25 matching lines @@
 }
 
 .safe .controls a {
   display: inline;
 }
 
 #downloads-pagination {
   -webkit-margin-start: 18px;
   padding-top: 24px;
 }