Revert "Use tree path recovery in ChromeVox"

This reverts commit 24083475.

Reason for revert: <INSERT REASONING HERE>
This is a heavy handed workaround for issues in Blink. Root cause was fixed in Blink.
https://chromium-review.googlesource.com/c/chromium/src/+/1872422

Original change's description:
> 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/+/1872557
> Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
> Commit-Queue: David Tseng <dtseng@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#708044}

TBR=dmazzoni@chromium.org,dtseng@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: If87d5b96c4f658bce34098466c4a240ac38490dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1922915Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#716865}

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

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