After bug 1662587, content process will send a message to the parent process to request pointer lock and wait for parent process response, I suspect we don't handle some cases properly, for example, the page that requests pointer lock lose the focus before getting the response. I will look into this closely tomorrow.
Bug 1684837 Comment 6 Edit History
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After bug 1662587, content process will send a message to the parent process to request pointer lock and wait for parent process response, I suspect we don't handle some cases properly, for example, the page that requests pointer lock lose the focus before getting the response from parent process. I will look into this closely tomorrow.