wrench_menu: use NativeTheme colors under aura

ui/native_theme/native_theme_aura.cc

Index: ui/native_theme/native_theme_aura.cc
diff --git a/ui/native_theme/native_theme_aura.cc b/ui/native_theme/native_theme_aura.cc
index b1f41e42fe8b9443b6d4066c791b6dce8d6d826f..ae54d967717e50999ce7cecf9fd742b541fa3186 100644
--- a/ui/native_theme/native_theme_aura.cc
+++ b/ui/native_theme/native_theme_aura.cc
@@ -38,6 +38,7 @@ const SkColor kTextButtonHoverColor = kTextButtonEnabledColor;
 const SkColor kEnabledMenuItemForegroundColor = kTextButtonEnabledColor;
 const SkColor kDisabledMenuItemForegroundColor = kTextButtonDisabledColor;
 const SkColor kFocusedMenuItemBackgroundColor = SkColorSetRGB(0xF1, 0xF1, 0xF1);
+const SkColor kHoverMenuItemBackgroundColor = SkColorSetRGB(204, 204, 204);
 const SkColor kMenuSeparatorColor = SkColorSetRGB(0xED, 0xED, 0xED);
 // Label:
 const SkColor kLabelEnabledColor = kTextButtonEnabledColor;
@@ -130,6 +131,8 @@ SkColor NativeThemeAura::GetSystemColor(ColorId color_id) const {
       return kDisabledMenuItemForegroundColor;
     case kColorId_FocusedMenuItemBackgroundColor:
       return kFocusedMenuItemBackgroundColor;
+    case kColorId_HoverMenuItemBackgroundColor:
+      return kHoverMenuItemBackgroundColor;
     case kColorId_MenuSeparatorColor:
       return kMenuSeparatorColor;