Removed a context menu from Files.app's left nav, since it became redundant.

chrome/browser/resources/file_manager/css/file_manager.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 {
   height: 100%;
 }
 
 html.col-resize * {
   cursor: col-resize !important;
@@ skipping 1549 matching lines @@
   padding: 10px;
   position: absolute;
   right: 0;
   top: 28px;  /* Leave room for the file list header. */
 }
 
 .dialog-container:not([drive-welcome='page']) #no-search-results[show] {
   display: block;
 }
 
-#downloads-root-context-menu {
-  min-width: 250px;
-}
-
-#drive-space-info,
-#downloads-space-info {
+#drive-space-info {
   -webkit-box-pack: justify;
   display: -webkit-box;
 }
 
-#drive-space-info-label,
-#downloads-space-info-label {
+#drive-space-info-label {
   display: block;
 }
 
-#drive-space-info > div,
-#downloads-space-info > div {
+#drive-space-info > div {
   -webkit-box-flex: 1;
   border: 1px solid rgb(192, 192, 192);
   display: block;
   height: 11px;
   margin: 8px 0 9px 10px;
   min-width: 30px;
 }
 
-#drive-space-info-bar[pending],
-#downloads-space-info-bar[pending] {
+#drive-space-info-bar[pending] {
   -webkit-animation-duration: 800ms;
   -webkit-animation-iteration-count: infinite;
   -webkit-animation-name: bg;
   -webkit-animation-timing-function: linear;
   background-color: rgb(192, 192, 192);
   background-image: -webkit-linear-gradient(315deg, transparent,
       transparent 33%, rgba(0, 0, 0, 0.12) 33%, rgba(0, 0, 0, 0.12) 66%,
       transparent 66%, transparent);
   background-position: 0 0;
   background-repeat: repeat-x;
   background-size: 16px 8px;
 }
 
-#drive-space-info-bar,
-#downloads-space-info-bar {
+#drive-space-info-bar {
   background-color: rgb(192, 192, 192);
   border: 1px solid rgb(255, 255, 255);
   box-sizing: border-box;
   height: 100%;
   width: 50%;
 }
 
 #list-container .table-header-inner {
   height: 100%;
 }
@@ skipping 12 matching lines @@
 
 #default-action-dialog {
   min-width: 300px;
   width: auto;
 }
 
 .drive-welcome-wrapper {
   /* drive_welcome.css will override it once loaded. */
   display: none;
 }