Add support for in-page links in ChromeVox.

chrome/common/extensions/api/automation.idl

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // The <code>chrome.automation</code> API allows developers to access the
 // automation (accessibility) tree for the browser. The tree resembles the DOM
 // tree, but only exposes the <em>semantic</em> structure of a page. It can be
 // used to programmatically interact with a page by examining names, roles, and
 // states, listening for events, and performing actions on nodes.
 [nocompile] namespace automation {
@@ skipping 425 matching lines @@
 
     // The nodes, if any, which form a label for this element. Generally, the
     // text from these elements will also be exposed as the element's accessible
     // name, via the $(ref:automation.AutomationNode.name) attribute.
     AutomationNode[]? labelledBy;
 
     // The node referred to by <code>aria-activedescendant</code>, where
     // applicable
     AutomationNode? activeDescendant;
 
+    // The target of an in-page link.
+    AutomationNode? inPageLinkTarget;
+
     //
     // Link attributes.
     //
 
     // The URL that this link will navigate to.
     DOMString? url;
 
     //
     // Document attributes.
     //
@@ skipping 296 matching lines @@
 
   // Called with the <code>AutomationNode</code> that currently has focus.
   callback FocusCallback = void(AutomationNode focusedNode);
 
   interface Functions {
     // Get the automation tree for the tab with the given tabId, or the current
     // tab if no tabID is given, enabling automation if necessary. Returns a
     // tree with a placeholder root node; listen for the "loadComplete" event to
     // get a notification that the tree has fully loaded (the previous root node
     // reference will stop working at or before this point).
-    [nocompile] static void getTree(optional long tabId, RootCallback callback);
+    [nocompile] static void getTree(optional long tabId,
+                                    optional RootCallback callback);
 
     // Get the automation tree for the whole desktop which consists of all on
     // screen views. Note this API is currently only supported on Chrome OS.
     [nocompile] static void getDesktop(RootCallback callback);
 
     // Get the automation node that currently has focus, globally. Will return
     // null if none of the nodes in any loaded trees have focus.
     [nocompile] static void getFocus(FocusCallback callback);
 
     // Add a tree change observer. Tree change observers are static/global, they
@@ skipping 12 matching lines @@
     // Everything in the tree between the two node/offset pairs gets included
     // in the selection. The anchor is where the user started the selection,
     // while the focus is the point at which the selection gets extended
     // e.g. when dragging with a mouse or using the keyboard. For nodes with
     // the role staticText, the offset gives the character offset within
     // the value where the selection starts or ends, respectively.
     [nocompile] static void setDocumentSelection(
         SetDocumentSelectionParams params);
   };
 };