Migrate WebKit "global script" font prefs.

chrome/common/extensions/api/experimental_font_settings.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace": "experimental.fontSettings",
     "types": [
       {
         "id": "FontName",
         "type": "object",
         "description": "Represents a font name.",
         "properties": {
           "fontName": {
             "type": "string",
             "description": "The font name."
           },
           "localizedName": {
             "type": "string",
             "description": "The font name localized for the current locale."
           }
         }
       },
       {
         "id": "ScriptCode",
         "type": "string",
         "enum": [ "Arab", "Armn", "Beng", "Cans", "Cher", "Cyrl", "Deva", "Ethi", "Geor",
                   "Grek", "Gujr", "Guru", "Hang", "Hans", "Hant", "Hebr", "Hrkt", "Knda",
                   "Khmr", "Laoo", "Mlym", "Mong", "Mymr", "Orya", "Sinh", "Taml", "Telu",
-                  "Thaa", "Thai", "Tibt", "Yiii"
+                  "Thaa", "Thai", "Tibt", "Yiii", "Zyyy"
                 ],
-        "description": "An ISO 15924 script code."
+        "description": "An ISO 15924 script code. The default, or global, script is represented by script code \"Zyyy\"."
       },
       {
         "id": "GenericFamily",
         "type": "string",
         "enum": ["standard", "sansserif", "serif", "fixed", "cursive", "fantasy"],
         "description": "A CSS generic font family."
       },
       {
         "id": "LevelOfControl",
         "description": "One of<br><var>not_controllable</var>: cannot be controlled by any extension<br><var>controlled_by_other_extensions</var>: controlled by extensions with higher precedence<br><var>controllable_by_this_extension</var>: can be controlled by this extension<br><var>controlled_by_this_extension</var>: controlled by this extension",
@@ skipping 32 matching lines @@
       {
         "name": "getFont",
         "description": "Gets the font for a given script and generic font family.",
         "parameters": [
           {
             "name": "details",
             "type": "object",
             "properties": {
               "script": {
                 "$ref": "ScriptCode",
-                "description": "The script for which the font should be retrieved. If omitted, the font for the global script is retrieved.",
+                "description": "The script for which the font should be retrieved. If omitted, the font setting for the global script (script code \"Zyyy\") is retrieved.",
                 "optional": true
               },
               "genericFamily": {
                 "$ref": "GenericFamily",
                 "description": "The generic font family for which the font should be retrieved."
               }
             }
           },
           {
             "type": "function",
@@ skipping 21 matching lines @@
       {
         "name": "setFont",
         "description": "Sets the font for a given script and generic font family.",
         "parameters": [
           {
             "name": "details",
             "type": "object",
             "properties": {
               "script": {
                 "$ref": "ScriptCode",
-                "description": "The script code which the font should be set. If omitted, the font for the global script is set.",
+                "description": "The script code which the font should be set. If omitted, the font setting for the global script (script code \"Zyyy\") is set.",
                 "optional": true
               },
               "genericFamily": {
                 "$ref": "GenericFamily",
                 "description": "The generic font family for which the font should be set."
               },
               "fontName": {
                 "type": "string",
                 "description": "The font name. If a script is specified, the empty string means to fallback to the global script font setting."
               }
@@ skipping 330 matching lines @@
         "name": "onFontChanged",
         "description": "Fired when a font setting changes.",
         "parameters": [
           {
             "type": "object",
             "name": "details",
             "properties": {
               "fontName": { "type": "string" },
               "script": {
                 "$ref": "ScriptCode",
-                "description": "The script code for which the font setting has changed. If omitted, the global script font setting has changed.",
+                "description": "The script code for which the font setting has changed.",
                 "optional": true
               },
               "genericFamily": {
                 "$ref": "GenericFamily",
                 "description": "The generic font family for which the font setting has changed."
               },
               "levelOfControl": {
                 "$ref": "LevelOfControl",
                 "description": "The level of control this extension has over the setting."
               }
@@ skipping 77 matching lines @@
                 "$ref": "LevelOfControl",
                 "description": "The level of control this extension has over the setting."
               }
             }
           }
         ]
       }
     ]
   }
 ]