Fix docs.dart, which has been sad and neglected.

tools/dom/docs/docs.json

 {
   "dart.dom.html": {
     "CanvasGradient": {
       "comment": [
         "/**",
         " * An opaque canvas object representing a gradient.",
         " *",
         " * Created by calling [createLinearGradient] or [createRadialGradient] on a",
         " * [CanvasRenderingContext2D] object.",
         " *",
@@ skipping 325 matching lines @@
         " * as specified by [WebSocketEvents].",
         " *",
         " * For more information, see the",
         " * [WebSockets](http://www.dartlang.org/docs/library-tour/#html-websockets)",
         " * section of the library tour and",
         " * [Introducing WebSockets](http://www.html5rocks.com/en/tutorials/websockets/basics/),",
         " * an HTML5Rocks.com tutorial.",
         " */"
       ]
     },
+    "WorkerContext": {
+      "members": {
+        "webkitRequestFileSystem": [
+          "/**",
+          "   * Access a sandboxed file system of the specified `size`. If `persistent` is",
+          "   * true, the application will request permission from the user to create",
+          "   * lasting storage. This storage cannot be freed without the user's",
+          "   * permission. Returns a [Future] whose value stores a reference to the",
+          "   * sandboxed file system for use. Because the file system is sandboxed,",
+          "   * applications cannot access file systems created in other web pages. ",
+          "   */"
+        ],
+        "webkitRequestFileSystemSync": [
+          "/**",
+          "   * Access a sandboxed file system of the specified `size`. If `persistent` is",
+          "   * true, the application will request permission from the user to create",
+          "   * lasting storage. This storage cannot be freed without the user's",
+          "   * permission. This call will block until a reference to the synchronous file ",
+          "   * system API has been obtained. Because the file system is sandboxed,",
+          "   * applications cannot access file systems created in other web pages. ",
+          "   */"
+        ]
+      }
+    },
     "XMLHttpRequest": {
       "members": {
         "abort": [
           "/**",
           "   * Stop the current request.",
           "   *",
           "   * The request can only be stopped if readyState is `HEADERS_RECIEVED` or",
           "   * `LOADING`. If this method is not in the process of being sent, the method",
           "   * has no effect.",
           "   */"
@@ skipping 221 matching lines @@
           "   *",
           "   * [oldVersion] should match the database's current [version] exactly.",
           "   *",
           "   * * [Database.changeVersion](http://www.w3.org/TR/webdatabase/#dom-database-changeversion) from W3C.",
           "   */"
         ]
       }
     }
   }
 }