Updated top level docs for Window.

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 292 matching lines @@
           "/**",
           "   * Transmit data to the server over this connection.",
           "   *",
           "   * This method accepts data of type [Blob], [ByteBuffer], [String], or",
           "   * [TypedData]. Named variants [sendBlob], [sendByteBuffer], [sendString],",
           "   * or [sendTypedData], in constrast, only accept data of the specified type.",
           "   */"
         ]
       }
     },
+    "Window": {
+      "comment": [
+        "/**",
+        " * Top-level container for the current browser tab or window.",
+        " *",
+        " * In a web browser, each window has a [Window] object, but within the context",
+        " * of a script, a [Window] object represents only the current window. In",
+        " * addition to the open window, each window, tab, and iframe has its own",
+        " * [Window] object. A [Window] contains a [Document] object, which contains this",
+        " * web page's content.",
+        " *",
+        " * Use `window` to access properties of the current window. For example:",
+        " *",
+        " *     // Draw a scene when the window repaints.",
+        " *     drawScene(num delta) {...}",
+        " *     window.animationFrame.then(drawScene);.",
+        " *",
+        " *     // Write to the console.",
+        " *     window.console.log('Jinkies!');",
+        " *     window.console.error('Jeepers!');",
+        " *",
+        " * **Note:** This class represents the current window, whereas [WindowBase] is",
+        " * a representation of any window, including other tabs, windows, and frames.",
+        " *",
+        " * ## Other resources",
+        " *",
+        " * * [DOM Window](https://developer.mozilla.org/en-US/docs/DOM/window) from MDN.",
+        " * * [Window](http://www.w3.org/TR/Window/) 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 290 matching lines @@
           "   *",
           "   * [oldVersion] should match the database's current [version] exactly.",
           "   *",
           "   * * [Database.changeVersion](http://www.w3.org/TR/webdatabase/#dom-database-changeversion) from W3C.",
           "   */"
         ]
       }
     }
   }
 }