Add getFontList() to Font Settings Extension API.

chrome/common/extensions/api/experimental.fonts.json

 [
   {
     "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."
+          }
+        }
+      }
+    ],
     "functions": [
       {
         "name": "getFontName",
         "type": "function",
-        "description": "Gets the font name of the current setting for a given script and font family.",
+        "description": "Gets the font name of the current setting for a given script and generic font family.",
         "parameters": [
           {
             "name": "details",
             "type": "object",
             "properties": {
               "script": {
                 "type": "string",
                 "enum": ["Arab", "Hang", "Hans", "Hant", "Hrkt"],
                 "description": "The ISO 15924 script code for which the font setting should be retrieved. If omitted, the global script font setting is retrieved.",
                 "optional": true
@@ skipping 20 matching lines @@
                   }
                 }
               }
             ]
           }
         ]
       },
       {
         "name": "setFontName",
         "type": "function",
-        "description": "Sets the font name of the current setting for a given script and font family.",
+        "description": "Sets the font name of the current setting for a given script and generic font family.",
         "parameters": [
           {
             "name": "details",
             "type": "object",
             "properties": {
               "script": {
                 "type": "string",
                 "enum": ["Arab", "Hang", "Hans", "Hant", "Hrkt"],
                 "description": "The ISO 15924 script code for which the font setting should be retrieved. If omitted, the global script font setting is retrieved.",
                 "optional": true
               },
               "genericFamily": {
                 "type": "string",
                 "enum": ["standard", "sansserif", "serif", "fixed", "cursive", "fantasy"],
                 "description": "The CSS generic font family for which the font setting should be retrieved."
               },
               "fontName": {
                 "type": "string",
                 "description": "The font name."
               }
             }
           },
           {
             "type": "function",
             "name": "callback",
             "optional": "true",
             "parameters": []
           }
         ]
+      },
+      {
+        "name": "getFontList",
+        "type": "function",
+        "description": "Gets a list of fonts on the system.",
+        "parameters": [
+          {
+            "type": "function",
+            "name": "callback",
+            "parameters": [
+              {
+                "name": "results",
+                "type": "array",
+                "items": { "$ref": "FontName" }
+              }
+            ]
+          }
+        ]
       }
     ]
   }
 ]