Merge to M65: Android Accessibility: Avoiding Infinite loop of FrameLayouts in a11y tree

Initially https://chromium-review.googlesource.com/c/chromium/src/+/729145
ContentViewCore.java#b1735 shows that if the mWebContentsAccessibility was null or
not enabled, we just create it and enable it. The return value was null for these 2 cases.

This CL tries to get that behavior back and avoid loops.

Bug: 805014
Change-Id: I4c880cf3f6fc482559b3cc81a3afbe22ae2fd199
Reviewed-on: https://chromium-review.googlesource.com/927861
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/branch-heads/3325@{#527}
Cr-Branched-From: bc084a8b5afa3744a74927344e304c02ae54189f-refs/heads/master@{#530369}
4 files changed