DevTools: Split SoftDropdown out of ConsoleContextSelector

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

 /*
  * Copyright 2017 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 {
     height: 26px;
     text-align: left;
+    position: relative;
+    border: none;
+    background: none;
 }
 
 :host([disabled]) {
     opacity: .5;
 }
 
 :host .title {
     padding-right: 5px;
     width: 120px;
     overflow: hidden;
     text-overflow: ellipsis;
 }
 
 :host([data-keyboard-focus="true"]:focus)::before {
     content: "";
     position: absolute;
     top: 2px;
     left: 2px;
     right: 2px;
     bottom: 2px;
     border-radius: 2px;
     background: rgba(0, 0, 0, 0.08);
 }
 
 :host(.warning) {
     background: #ffd7d7 !important;
 }