Use tree path recovery in ChromeVox

With the on-going changes in the Blink tree, ChromeVox can once again not rely on nodes persisting their ids.

Blink may choose to destroy and re-create an entire subtree of nodes in reaction to a page making some kind of update. The actual DOM does not change, but Blink re-creates the accessibility subtree (resulting in new nodes, with new ids).

Note that ChromeVox has flip flopped on using tree path recovery in the past.
Related bugs:
885244
945708
(each of these were verified to work after this change).

Related changes:
https://chromium-review.googlesource.com/c/chromium/src/+/1889165
https://chromium-review.googlesource.com/c/chromium/src/+/1539262

Change-Id: I1c0bb78ce448c601d116aa90e408c36cab21b3d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1872557Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708044}

chrome/browser/resources/chromeos/chromevox/cvox2/background/cursors.js

@@ -96,7 +96,7 @@ cursors.Cursor = function(node, index) {
   /** @type {number} @private */
   this.index_ = index;
   /** @type {RecoveryStrategy} */
-  this.recovery_ = new AncestryRecoveryStrategy(node);
+  this.recovery_ = new TreePathRecoveryStrategy(node);
 };
 
 /**