Revert of force non-overlay scrollbars in all platform in flamechart

third_party/WebKit/Source/devtools/front_end/perf_ui/flameChart.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.
  */
 
 .flame-chart-main-pane {
     overflow: hidden;
 }
 
@@ skipping 15 matching lines @@
 
 .flame-chart-selected-element {
     position: absolute;
     pointer-events: none;
     outline: 2px solid rgb(56, 121, 217);
     background-color: rgba(56, 121, 217, 0.1);
 }
 
 .flame-chart-v-scroll {
     position: absolute;
+    top: 0;
+    right: 0;
+    bottom: 0;
     overflow-x: hidden;
     z-index: 200;
     padding-left: 1px;
-    right: 2px;
-    top: 3px;
-    bottom: 3px;
 }
 
 .flame-chart-v-scroll.always-show-scrollbar {
     overflow-y: scroll;
 }
 
+:host-context(.platform-mac) .flame-chart-v-scroll {
+    right: 2px;
+    top: 3px;
+    bottom: 3px;
+}
+
 /* force non-overlay scrollbars */
-::-webkit-scrollbar {
+:host-context(.platform-mac) ::-webkit-scrollbar {
     width: 8px;
 }
 
-::-webkit-scrollbar-thumb {
+:host-context(.platform-mac) ::-webkit-scrollbar-thumb {
     background-color: hsla(0, 0%, 56%, 0.6);
     border-radius: 50px;
 }
 
-.flame-chart-v-scroll:hover::-webkit-scrollbar-thumb {
+:host-context(.platform-mac) .flame-chart-v-scroll:hover::-webkit-scrollbar-thumb {
     background-color: hsla(0, 0%, 25%, 0.6);
 }
 
 .flame-chart-selection-overlay {
     position: absolute;
     z-index: 100;
     background-color: rgba(56, 121, 217, 0.3);
     border-color: rgb(16, 81, 177);
     border-width: 0 1px;
     border-style: solid;
@@ skipping 43 matching lines @@
     white-space: nowrap;
 }
 
 .flame-chart-entry-info table tr td:first-child {
     font-weight: bold;
 }
 
 .flame-chart-entry-info table tr td span {
     margin-right: 5px;
 }