osr: linux: Crash after sending key events with ozone-platform=headless

[aleitner]

Describe the bug A crash occurs in a Linux environment when sending a key event for a key down press followed by a call to browser->get_host(browser); This issue is observed when using the spotify precompiled binary for version 133.4.5+gdb28106+chromium-133.0.6943.142 in headless mode. The crash does not occur in version 132.x.

To Reproduce Steps to reproduce the behavior:

1. Start the application with the following flags:

   execl(CEF_PROCESS_PATH, "cefclient",
         "--ozone-platform=headless",
         "--off-screen-rendering-enabled",
         "--disable-gpu-shader-disk-cache",
         (char*) NULL);
   

2. Send a key down event with the following properties:

   modifiers: 0
   js_key_code: 65
   unicode_char: 'a'
   unmodified_character: 97
   type: KEYEVENT_RAWKEYDOWN
   

3. Immediately send a second event with the same data but with type: KEYEVENT_CHAR if the dispatch character is a printable character.
4. Application crashes after these events are sent.

Expected behavior The application should not crash, and the key events should be processed successfully as they were in version 132.x.

Versions (please complete the following information):

• OS: Ubuntu 22.04.1 LTS, Kernel version 6.8.0-1021-aws
• CEF Version: 133.4.5+gdb28106+chromium-133.0.6943.142

Additional context

• The issue persists even when running with the --off-screen-rendering-enabled flag.
• The crash message indicates a failure check in browser_platform_delegate_native_linux.cc at line 276 with the message: FATAL:browser_platform_delegate_native_linux.cc(276)] Check failed: false.
• The problem does not reproduce with version 132.x of the spotify precompiled binary.
• This might be related to changes in Chromium that affect how key events are handled or processed in the Linux environment for version 133.x.

This issue needs further investigation to understand the changes between versions 132.x and 133.x that might be causing this crash.