[Lacros] Pop-up menus should use Chrome OS styling.

Temporarily add explicit border around pop-up menus since we aren't
yet drawing drop-shadows for pop-up menus.

Bug: 1156893
Change-Id: I7a8f2da5842d1ccf0da1a1fc0113dd55771d5afc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2580401Reviewed-by: Erik Chen <erikchen@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Darin Fisher <darin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#835311}

ui/views/BUILD.gn

@@ -548,14 +548,17 @@ component("views") {
       "linux_ui/window_button_order_observer.h",
     ]
     sources += [
-      "controls/menu/menu_config_linux.cc",
       "linux_ui/linux_ui.cc",
       "linux_ui/status_icon_linux.cc",
       "linux_ui/window_button_order_provider.cc",
     ]
+
+    if (!is_chromeos_lacros) {
+      sources += [ "controls/menu/menu_config_linux.cc" ]
+    }
   }
 
-  if (is_chromeos_ash) {
+  if (is_chromeos_ash || is_chromeos_lacros) {
     sources += [ "controls/menu/menu_config_chromeos.cc" ]
   }
 

ui/views/controls/menu/menu_config_chromeos.cc

@@ -4,6 +4,7 @@
 
 #include "ui/views/controls/menu/menu_config.h"
 
+#include "build/chromeos_buildflags.h"
 #include "ui/views/controls/menu/menu_image_util.h"
 
 namespace views {
@@ -22,8 +23,13 @@ void MenuConfig::Init() {
   offset_context_menus = true;
   corner_radius = 2;
 
+#if BUILDFLAG(IS_CHROMEOS_LACROS)
+  // TODO(crbug/1129012): Change to false once pop-up menus have shadows.
+  use_outer_border = true;
+#else
   // In Ash, the border is provided by the shadow.
   use_outer_border = false;
+#endif
 }
 
 }  // namespace views