Convert the overlay scrollbar flag to use FeatureList

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index b9f0d3a60af187b13faaef4751778f0f7eba4cf5..ef36bf9b4ebccd433163f7e3894f06e61b612ab5 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -200,7 +200,7 @@
 #include "ui/gfx/switches.h"
 #include "ui/gl/gl_switches.h"
 #include "ui/gl/gpu_switching_manager.h"
-#include "ui/native_theme/native_theme_switches.h"
+#include "ui/native_theme/native_theme_features.h"
 
 #if defined(OS_ANDROID)
 #include "content/public/browser/android/java_interfaces.h"
@@ -1705,7 +1705,6 @@ void RenderProcessHostImpl::PropagateBrowserCommandLineToRenderer(
     switches::kDisableLogging,
     switches::kDisableMediaSuspend,
     switches::kDisableNotifications,
-    switches::kDisableOverlayScrollbar,
     switches::kDisablePepper3DImageChromium,
     switches::kDisablePermissionsAPI,
     switches::kDisablePresentationAPI,
@@ -1743,7 +1742,6 @@ void RenderProcessHostImpl::PropagateBrowserCommandLineToRenderer(
     switches::kEnableLCDText,
     switches::kEnableLogging,
     switches::kEnableNetworkInformation,
-    switches::kEnableOverlayScrollbar,
     switches::kEnableNewVp9CodecString,
     switches::kEnablePinch,
     switches::kEnablePluginPlaceholderTesting,