Reland of [DevTools] Migrate SoftContextMenu to use GlassPane

third_party/WebKit/Source/devtools/front_end/ui/softContextMenu.css

 /*
  * Copyright (c) 2014 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.
  */
 
-:host {
-    position: absolute;
+.soft-context-menu {
     border: 1px solid rgba(196, 196, 196, 0.9);
     border-top: 1px solid rgba(196, 196, 196, 0.5);
-    /* NOTE: Keep padding top in sync with topPadding in SoftContextMenu.js */
+    /* NOTE: Keep padding in sync with padding adjustment in SoftContextMenu.js */
     padding: 4px 0 4px 0;
     border-radius: 4px;
     background-color: rgb(240, 240, 240);
     box-shadow: 0 5px 10px rgba(0, 0, 0, 0.25);
     overflow-y: auto;
     min-width: 160px !important;
 }
 
 .soft-context-menu-item {
     display: flex;
@@ skipping 76 matching lines @@
 
 .checkmark {
     opacity: 0.7;
     pointer-events: none;
     margin: auto 5px auto 0px;
 }
 
 .soft-context-menu-item-mouse-over .checkmark {
     opacity: 1;
 }