change overlay scrollbar hover show to hover fade in

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 1cf1b5318b176cbb1eefc8fa28e5b2f7fe536704..75e81c2e7bd2ade2b8a5c18bd785f317efa15d2a 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -444,11 +444,10 @@ cc::LayerTreeSettings RenderWidgetCompositor::GenerateLayerTreeSettings(
 #if !defined(OS_MACOSX)
   if (ui::IsOverlayScrollbarEnabled()) {
     settings.scrollbar_animator = cc::LayerTreeSettings::AURA_OVERLAY;
-    settings.scrollbar_show_delay = ui::kOverlayScrollbarShowDelay;
-    settings.scrollbar_fade_out_delay = ui::kOverlayScrollbarFadeOutDelay;
-    settings.scrollbar_fade_out_resize_delay =
-        ui::kOverlayScrollbarFadeOutDelay;
-    settings.scrollbar_fade_out_duration = ui::kOverlayScrollbarFadeOutDuration;
+    settings.scrollbar_fade_in_delay = ui::kOverlayScrollbarFadeDelay;
+    settings.scrollbar_fade_out_delay = ui::kOverlayScrollbarFadeDelay;
+    settings.scrollbar_fade_out_resize_delay = ui::kOverlayScrollbarFadeDelay;
+    settings.scrollbar_fade_duration = ui::kOverlayScrollbarFadeDuration;
     settings.scrollbar_thinning_duration =
         ui::kOverlayScrollbarThinningDuration;
   } else {
@@ -459,8 +458,7 @@ cc::LayerTreeSettings RenderWidgetCompositor::GenerateLayerTreeSettings(
     settings.scrollbar_fade_out_delay = base::TimeDelta::FromMilliseconds(500);
     settings.scrollbar_fade_out_resize_delay =
         base::TimeDelta::FromMilliseconds(500);
-    settings.scrollbar_fade_out_duration =
-        base::TimeDelta::FromMilliseconds(300);
+    settings.scrollbar_fade_duration = base::TimeDelta::FromMilliseconds(300);
   }
 #endif  // !defined(OS_MACOSX)