Cleaning up document.query

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 91 matching lines @@
         ],
         "createElement": [
           "/// Deprecated: use new Element.tag(tagName) instead."
         ],
         "createTouchList": [
           "/// Use the [TouchList] constructor instead."
         ],
         "getCSSCanvasContext": [
           "/// Moved to [HtmlDocument]."
         ],
-        "getElementById": [
-          "/// Deprecated: use query(\"#$elementId\") instead."
-        ],
         "head": [
           "/// Moved to [HtmlDocument]."
         ],
         "lastModified": [
           "/// Moved to [HtmlDocument]."
         ],
         "querySelector": [
-          "/// Deprecated: renamed to the shorter name [query]."
+          "/**",
+          " * Finds the first descendant element of this document that matches the",
+          " * specified group of selectors.",
+          " *",
+          " * Unless your webpage contains multiple documents, the top-level query",
+          " * method behaves the same as this method, so you should use it instead to",
+          " * save typing a few characters.",
+          " *",
+          " * [selectors] should be a string using CSS selector syntax.",
+          " *     var element1 = document.query('.className');",
+          " *     var element2 = document.query('#id');",
+          " *",
+          " * For details about CSS selector syntax, see the",
+          " * [CSS selector specification](http://www.w3.org/TR/css3-selectors/).",
+          " */"
         ],
         "querySelectorAll": [
           "/// Deprecated: use query(\"#$elementId\") instead."
         ],
         "referrer": [
           "/// Moved to [HtmlDocument]."
         ],
         "styleSheets": [
           "/// Moved to [HtmlDocument]"
         ],
@@ skipping 19 matching lines @@
           "/// Moved to [HtmlDocument]."
         ],
         "webkitIsFullScreen": [
           "/// Moved to [HtmlDocument]."
         ],
         "webkitPointerLockElement": [
           "/// Moved to [HtmlDocument]."
         ]
       }
     },
+    "Element": {
+      "members": {
+        "querySelector": [
+          "/**",
+          " * Finds the first descendant element of this element that matches the",
+          " * specified group of selectors.",
+          " *",
+          " * [selectors] should be a string using CSS selector syntax.",
+          " *",
+          " *     // Gets the first descendant with the class 'classname'",
+          " *     var element = element.query('.className');",
+          " *     // Gets the element with id 'id'",
+          " *     var element = element.query('#id');",
+          " *     // Gets the first descendant [ImageElement]",
+          " *     var img = element.query('img');",
+          " *",
+          " * See also:",
+          " *",
+          " * * [CSS Selectors](http://docs.webplatform.org/wiki/css/selectors)",
+          " */"
+        ]
+      }
+    },
     "HTMLAreaElement": {
       "comment": [
         "/**",
         " * DOM Area Element, which links regions of an image map with a hyperlink.",
         " *",
         " * The element can also define an uninteractive region of the map.",
         " *",
         " * See also:",
         " *",
         " * * [<area>](https://developer.mozilla.org/en-US/docs/HTML/Element/area)",
@@ skipping 370 matching lines @@
           "   * Otherwise, [errorCallback] is called.",
           "   *",
           "   * [oldVersion] should match the database's current [version] exactly.",
           "   *",
           "   * * [Database.changeVersion](http://www.w3.org/TR/webdatabase/#dom-database-changeversion) from W3C.",
           "   */"
         ]
       }
     }
   }
-}
+}