DevTools: Show preview in console of ES6 Map, Set, WeakMap and WeakSet entries.

Source/devtools/front_end/inspectorStyle.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 1138 matching lines @@
 .console-group-messages .outline-disclosure li .selection {
     margin-left: -6px;
     margin-right: -6px;
 }
 
 .console-group-messages .add-attribute {
     display: none;
 }
 
 .console-formatted-object,
+.console-formatted-map,
+.console-formatted-set,
 .console-formatted-node,
 .console-formatted-array {
     position: relative;
     display: inline-block;
     vertical-align: top;
     color: inherit;
 }
 
 .console-formatted-node:hover {
     background-color: rgba(56, 121, 217, 0.1);
 }
 
 .console-formatted-object .section,
+.console-formatted-map .section,
+.console-formatted-set .section,
 .console-formatted-node .section,
 .console-formatted-array .section {
     position: static;
 }
 
 .console-formatted-object .section > .header::before {
     margin-top: 0;
 }
 
 .console-formatted-object .properties,
+.console-formatted-map .properties,
+.console-formatted-set .properties,
 .console-formatted-node .properties {
     padding-left: 0 !important;
 }
 
 .console-formatted-number,
 .console-formatted-boolean {
     color: rgb(28, 0, 207);
 }
 
 .console-formatted-string,
@@ skipping 536 matching lines @@
     right: 8px;
     display: none;
 }
 
 .section .properties li.hovered .delete-button {
     display: inline;
 }
 
 .section .properties .name,
 .event-properties .name,
-.console-formatted-object .name {
+.console-object-preview .name {
     color: rgb(136, 19, 145);
 }
 
 .section .properties .dimmed {
     opacity: 0.6;
 }
 
 .section .properties .value.error {
     color: red;
 }
@@ skipping 1030 matching lines @@
 }
 
 body.inactive select.chrome-select,
 .chrome-select:disabled {
     background-image: -webkit-image-set(url(Images/chromeDisabledSelect.png) 1x, url(Images/chromeDisabledSelect_2x.png) 2x), linear-gradient(#f1f1f1, #f1f1f1 38%, #e6e6e6);
     border-color: rgba(80, 80, 80, 0.2);
     box-shadow: 0 1px 0 rgba(80, 80, 80, 0.08),
     inset 0 1px 2px rgba(255, 255, 255, 0.75);
     color: #aaa;
 }