DevTools: make toolbar button click targets square

Source/devtools/front_end/components/inspectorViewTabbedPane.css

 /*
  * Copyright 2015 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.
  */
 
 .tabbed-pane-header {
     background-color: #f3f3f3;
-    flex: 0 0 24px;
-}
-
-:host-context(.material) .tabbed-pane-header {
-    flex: 0 0 29px;
+    flex: 0 0 27px;
     overflow: visible;
 }
 
-:host-context(.material) .tabbed-pane-header-tab {
-    height: 28px;
-    border: none;
+.tabbed-pane-header-tab {
     transition: background-color 100ms cubic-bezier(0.4, 0, 0.2, 1);
 }
 
 .tabbed-pane-header-tab:hover {
-    background-color: rgba(105, 105, 105, 0.1);
+    background-color: rgba(105, 105, 105, 0.1) !important;
 }
 
 .tabbed-pane-header-tab,
 .tabbed-pane-header-tab.selected {
-    border: none;
-    height: 23px;
+    height: 26px;
     margin: 0;
     background: none;
     border: none;
     padding: 0 6px;
     transition: background-color 150ms cubic-bezier(0, 0, 0.2, 1);
 }
 
 .tabbed-pane-header-tab {
     color: #666;
 }
 
 .tabbed-pane-header-tab.selected {
     color: #333;
 }
-
-:host-context(body.undocked.platform-mac) .tabbed-pane-header {
-    background-color: rgb(243, 243, 243);
-    color: #333 !important;
-}