macviews: use new menu spacings

Latest revisions from UX in comment 17 on the linked bug:

Text items reduced from 32 to 28
Container items reduced from 48 to 40 (not specced, but not doing this made
them look very weird)
Separator spacing reduced from 8pt to 4pt

Bug: 860673
Change-Id: Iad700a22eb9aad43f2c328314a6bffa885843194
Reviewed-on: https://chromium-review.googlesource.com/1148467
Commit-Queue: Sidney San Martín <sdy@chromium.org>
Reviewed-by: Sidney San Martín <sdy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577908}

ui/views/controls/menu/menu_config_mac.mm

@@ -16,18 +16,18 @@ void InitMaterialMenuConfig(views::MenuConfig* config) {
   // images linked from that bug.
   config->menu_horizontal_border_size = 0;
   config->submenu_horizontal_inset = 0;
-  config->minimum_text_item_height = 32;
-  config->minimum_container_item_height = 48;
+  config->minimum_text_item_height = 28;
+  config->minimum_container_item_height = 40;
   config->minimum_menu_width = 320;
   config->label_to_arrow_padding = 0;
   config->arrow_to_edge_padding = 16;
   config->check_width = 16;
   config->check_height = 16;
   config->arrow_width = 8;
-  config->separator_height = 17;
-  config->separator_lower_height = 9;
-  config->separator_upper_height = 9;
-  config->separator_spacing_height = 9;
+  config->separator_height = 9;
+  config->separator_lower_height = 4;
+  config->separator_upper_height = 4;
+  config->separator_spacing_height = 5;
   config->separator_thickness = 1;
   config->align_arrow_and_shortcut = true;
   config->use_outer_border = false;