Default to mode without native header to save space and use GTK+ theme by default for style consistency with the rest of the system

+ clean up of the config, removed odd and probably not working parts

chromium-default-config.json

@@ -1,29 +1,15 @@
 {
   "browser": {
-    "custom_chrome_frame": false
+    "custom_chrome_frame": true
   },
   "extensions": {
     "theme": {
-      "colors": {},
-      "id": "",
-      "images": {},
-      "properties": {},
-      "tints": {},
-      "use_system": false
+      "use_system": true
     }
   },
   "homepage": "https://rosalinux.ru",
   "homepage_is_newtabpage": false,
   "session": {
     "restore_on_startup": 1
-  },
-  "webkit": {
-    "webprefs": {
-      "default_fixed_font_size": 13,
-      "default_font_size": 16,
-      "fixed_font_family": "Droid Sans Mono",
-      "sansserif_font_family": "Droid Sans",
-      "serif_font_family": "Droid Serif"
-    }
   }
 }