Finished porting code from the old html-json docs.

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 232 matching lines @@
         " *     document.body.elements.add(elem);",
         " *",
         " * See also:",
         " *",
         " * * [HTML <div> element](http://www.w3.org/TR/html-markup/div.html) from W3C.",
         " * * [Block-level element](http://www.w3.org/TR/CSS2/visuren.html#block-boxes) from W3C.",
         " * * [Inline-level element](http://www.w3.org/TR/CSS2/visuren.html#inline-boxes) from W3C.",
         " */"
       ]
     },
+    "HTMLMenuElement": {
+      "comment": [
+        "/**",
+        " * An HTML <menu> element.",
+        " *",
+        " * A <menu> element represents an unordered list of menu commands.",
+        " *",
+        " * See also:",
+        " *",
+        " *  * [Menu Element](https://developer.mozilla.org/en-US/docs/HTML/Element/menu) from MDN.",
+        " *  * [Menu Element](http://www.w3.org/TR/html5/the-menu-element.html#the-menu-element) from the W3C.",
+        " */"
+      ]
+    },
     "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 11 matching lines @@
           "   */"
         ],
         "getResponseHeader": [
           "/**",
           "   * Return the response header named `header`, or `null` if not found.",
           "   *",
           "   * See also [HTTP response headers](http://en.wikipedia.org/wiki/List_of_HTTP_header_fields#Responses)",
           "   * for a list of common response headers.",
           "   */"
         ],
+        "onabort": [
+          "/**",
+          "   * Event listeners to be notified when request has been aborted,",
+          "   * generally due to calling `httpRequest.abort()`.",
+          "   */"
+        ],
+        "onerror": [
+          "/**",
+          "   * Event listeners to be notified when a request has failed, such as when a",
+          "   * cross-domain error occurred or the file wasn't found on the server.",
+          "   */"
+        ],
+        "onload": [
+          "/**",
+          "   * Event listeners to be notified once the request has completed",
+          "   * *successfully*.",
+          "   */"
+        ],
+        "onloadend": [
+          "/**",
+          "   * Event listeners to be notified once the request has completed (on",
+          "   * either success or failure).",
+          "   */"
+        ],
+        "onloadstart": [
+          "/**",
+          "   * Event listeners to be notified when the request starts, once",
+          "   * `httpRequest.send()` has been called.",
+          "   */"
+        ],
+        "onprogress": [
+          "/**",
+          "   * Event listeners to be notified when data for the request",
+          "   * is being sent or loaded.",
+          "   *",
+          "   * Progress events are fired every 50ms or for every byte transmitted,",
+          "   * whichever is less frequent.",
+          "   */"
+        ],
+        "onreadystatechange": [
+          "/**",
+          "   * Event listeners to be notified every time the [HttpRequest]",
+          "   * object's `readyState` changes values.",
+          "   */"
+        ],
         "open": [
           "/**",
           "   * Specify the desired `url`, and `method` to use in making the request.",
           "   *",
           "   * By default the request is done asyncronously, with no user or password",
           "   * authentication information. If `async` is false, the request will be send",
           "   * synchronously.",
           "   *",
           "   * Calling `open` again on a currently active request is equivalent to",
           "   * calling `abort`.",
@@ skipping 125 matching lines @@
           "   * is the (more verbose) equivalent of",
           "   *",
           "   *     var request = new HttpRequest.get('http://dartlang.org',",
           "   *         (event) => print('Request complete'));",
           "   */"
         ]
       }
     }
   }
 }