[FileBrowser] Added DefaultAction dialog to choose default action.

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.col-resize * {
   cursor: col-resize !important;
 }
 
 /* Outer frame of the dialog. */
 body {
@@ skipping 540 matching lines @@
   overflow: hidden;
   position: relative;
   width: 112px;
 }
 
 div.img-container > img {
   -webkit-user-drag: none;
   position: absolute;
 }
 
+/* Padding counterweights negative margins of items, thus eliminating scroll
+   bar when it's not needed. Max height is set to fit 8 items before showing
+   scroll bar. */
+#default-actions-list {
+  max-height: 328px;
+  padding: 1px 0;
+}
+
+#default-actions-list > li {
+  display: -webkit-box;
+}
+
+#default-actions-list > li > * {
+  display: block;
+  padding: 0 5px;
+}
+
+#default-actions-list > li > img {
+  height: 16px;
+  padding-top: 12px;
+}
+
+
 #list-container list > *,
-#list-container grid > * {
+#list-container grid > *,
+#default-actions-list > * {
   background-image: none;
   border-radius: 0;
   line-height: 30px;
 }
 
 #list-container list > [selected],
-#list-container grid > [selected] {
+#list-container grid > [selected],
+#default-actions-list > [selected] {
   background-color: rgb(203, 219, 241);
 }
 
-#list-container list > li.table-row[selected] {
+#list-container list > li.table-row[selected],
+#default-actions-list > li[selected] {
   border-top: 1px solid rgb(224, 233, 247);
 }
 
 #list-container list > .accepts[selected],
 #list-container grid > .accepts[selected],
 #list-container list > [selected]:hover,
-#list-container grid > [selected]:hover {
+#list-container grid > [selected]:hover,
+#default-actions-list > [selected]:hover {
   background-color: rgb(193, 211, 236);
 }
 
 #list-container list > .accepts,
 #list-container grid > .accepts,
 #list-container list > :hover,
-#list-container grid > :hover {
+#list-container grid > :hover,
+#default-actions-list > :hover {
   background-color: #f1f1f1;
 }
 
 #list-container.nohover list > :not([selected]):hover,
 #list-container.nohover grid > :not([selected]):hover {
   background-color: transparent;
   border-color: transparent;
 }
 
 .table-row-cell .filename-label,
@@ skipping 227 matching lines @@
 
 .file-checkbox:hover,
 .pin:hover,
 #list-container li.table-row[selected] .file-checkbox,
 #list-container li.table-row[selected] .pin,
 #list-container li.table-row .pin:checked,
 #list-container li.thumbnail-item[selected] .file-checkbox {
   opacity: 1 !important;
 }
 
-#list-container li.table-row {
+#list-container li.table-row,
+#default-actions-list li {
   border: none;
   border-top: 1px solid transparent;
   line-height: 39px;
   padding-bottom: 1px;
   padding-top: 1px;
 }
 
 /* The icon in the name column. */
 .detail-icon {
   background-image: url(../images/filetype_generic.png);
@@ skipping 444 matching lines @@
   left: 0;
   padding: 10px;
   position: absolute;
   right: 0;
   top: 28px;  /* Leave room for the file list header. */
 }
 
 .dialog-container:not([gdrive-welcome='page']) #no-search-results[show] {
   display: block;
 }