Enable overlay scrollbars on ChromeOS

content/renderer/render_view_browsertest.cc

Index: content/renderer/render_view_browsertest.cc
diff --git a/content/renderer/render_view_browsertest.cc b/content/renderer/render_view_browsertest.cc
index a3b4a3c0d41c9f3953dee4e9a3c556b5ebdd3266..344204d88b89cf0cc8df5cab0e7d946dc67076c2 100644
--- a/content/renderer/render_view_browsertest.cc
+++ b/content/renderer/render_view_browsertest.cc
@@ -84,6 +84,7 @@
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/gfx/codec/jpeg_codec.h"
 #include "ui/gfx/range/range.h"
+#include "ui/native_theme/native_theme_switches.h"
 
 #if defined(USE_AURA) && defined(USE_X11)
 #include <X11/Xlib.h>
@@ -220,6 +221,8 @@ class RenderViewImplTest : public RenderViewTest {
     // does not have to bother enabling each feature.
     WebRuntimeFeatures::enableExperimentalFeatures(true);
     WebRuntimeFeatures::enableTestOnlyFeatures(true);
+    WebRuntimeFeatures::enableOverlayScrollbars(
+        ui::IsOverlayScrollbarEnabled());
     RenderViewTest::SetUp();
   }