Steps to reproduce the problem:
1. change display size.
2. ActivityManager kill all background process.
3. Device reboot.

What is the expected behavior?

What went wrong?
1.WebViewLoader-arm64-v8a (pid 3672) has been killed at 23/10/2017,but when WebViewFactory which has started a WebViewLoader process, but did not notify ActivityManager to attach the process.
So, ActivityManager is also unaware that the process was gone.
2,So,when display size has changed,AMS kill all background.AMS kill WebViewLoader-arm64-v8a (pid 3672) due to “kill all background except” reason.
But Thread-126 of system_server has same tid 3672 as killed process(WebViewLoader-arm64-v8a). Therefore system_server be mis-killed and result device reset.

Did this work before? N/A 

Chrome version: 61.0.3163.100  Channel: stable
OS Version: Android O80
Flash Version: 

In general, the process will be attached to ActivityManager when it launched and ActivityManager will listen to the death recipient.
Therefore, ActivityManager will clear related data when process is gone.

ActivityThread.java
6887    public static void main(String[] args) {
…
6916        ActivityThread thread = new ActivityThread();
6917        thread.attach(false);
…
6731    private void attach(boolean system) {
…
6744            final IActivityManager mgr = ActivityManager.getService();
6745            try {
6746                //++[Debug]
6747                //: Log attach application
6748                if (PERF_LOG) {
6749                    Log.v(PERF_TAG, "attach ApplicationThread="
6750                            + Integer.toHexString(System.identityHashCode(mAppThread)));
6751                }
6752                //--[Debug]
6753                mgr.attachApplication(mAppThread);

ActivityManagerService.java
// register death recipient for the app
7019    private final boolean attachApplicationLocked(IApplicationThread thread,
7020            int pid) {
…
7065            AppDeathRecipient adr = new AppDeathRecipient(
7066                    app, pid, thread);
7067            thread.asBinder().linkToDeath(adr, 0);
7068            app.deathRecipient = adr;

However, the WebViewFactory create the process by its own and did not attached the process to ActivityManager.
In that case, ActivityManager will think the process is always there.
Once the pid was reused by other process, there has possibility to mis-killed other process.

WebViewFactory.java
660    private static class RelroFileCreator {
661        // Called in an unprivileged child process to create the relro file.
662        public static void main(String[] args) {
663            boolean result = false;

Many thanks