DevTools: introduce View: a named widget with the toolbar.

third_party/WebKit/Source/devtools/front_end/elements/elementsPanel.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 744 matching lines @@
 }
 
 .style-properties li.editing-sub-part {
     padding: 3px 6px 8px 18px;
     margin: -1px -6px -8px -6px;
     text-overflow: clip;
 }
 
 .properties-widget-section {
     padding: 2px 0px 2px 5px;
+    flex: none;
 }
 
 .sidebar-pane-section-toolbar {
     position: absolute;
     right: 0;
     bottom: 0;
     visibility: hidden;
     background-color: rgba(255, 255, 255, 0.9);
 }
 
 .styles-pane:not(.is-editing-style) .styles-section.matched-styles:not(.read-only):hover .sidebar-pane-section-toolbar {
     visibility: visible;
 }