[chromium-discuss] Crash about AXTreeUpdate -- is not in the tree and not the new root

[张晓峰]

We are developing browser that based on Chromium 63. Recently I met many
crashes in Android 9.0, all of them have the crash logs like below:

Abort message: '[FATAL:ax_snapshot_node_android_platform.cc(275)] 643 is
not in the tree and not the new root


I did some investigation on it, and it seems this code can only be called
after RenderFrameHostImpl::RequestAXTreeSnapshot, and from the background
from https://bugs.chromium.org/p/chromium/issues/detail?id=547648#c12, "AccessibilityMsg_SnapshotTree
should be called is if you trigger Android's "Now on Tap" feature".

I found the code was added in https://codereview.chromium.org/1073983005/,
seems for WebView.

However, I am sure that our cell phone never use "Now to tap" feature, what
is more, the browser we developed is a independent APK, so should
not interacted with any WebView interface.

So my question is, could you help or give some hints about why this happens?

I am looking forward your kindly reply, thanks a lot.