wrench_menu: use NativeTheme colors under aura

ui/native_theme/common_theme.cc

Index: ui/native_theme/common_theme.cc
diff --git a/ui/native_theme/common_theme.cc b/ui/native_theme/common_theme.cc
index 90e4db5ab9be6984be894752ec6cb8d82a22db49..a95f8ddcef3941f9bb828960509907159e6afba3 100644
--- a/ui/native_theme/common_theme.cc
+++ b/ui/native_theme/common_theme.cc
@@ -28,6 +28,7 @@ const SkColor kMenuBorderColor = SkColorSetRGB(0xBA, 0xBA, 0xBA);
 const SkColor kMenuSeparatorColor = SkColorSetRGB(0xE9, 0xE9, 0xE9);
 const SkColor kEnabledMenuItemForegroundColor = SK_ColorBLACK;
 const SkColor kDisabledMenuItemForegroundColor = SkColorSetRGB(161, 161, 146);
+const SkColor kHoverMenuItemBackgroundColor = SkColorSetRGB(204, 204, 204);
 
 }  // namespace
 
@@ -57,6 +58,9 @@ bool CommonThemeGetSystemColor(NativeTheme::ColorId color_id, SkColor* color) {
     case NativeTheme::kColorId_TextButtonDisabledColor:
       *color = kDisabledMenuItemForegroundColor;
       break;
+    case NativeTheme::kColorId_HoverMenuItemBackgroundColor:
+      *color = kHoverMenuItemBackgroundColor;
+      break;
     default:
       return false;
   }