Version: 51.0.2680.0 (Developer Build) (64-bit) with dcheck_always_on=1
OS: Linux

What steps will reproduce the problem?
don't know.
(1)
(2)
(3)

What is the expected output? What do you see instead?

browser process crashed for some reason.
[6639:6639:0318/142124:FATAL:media_web_contents_observer.cc(218)] Check failed: 
std::find((*player_map)[id.first].begin(), (*player_map)[id.first].end(), id.second) == (*player_map)[id.first].end().

Program received signal SIGABRT, Aborted.
0x00007fffeeec8cc9 in __GI_raise (sig=sig@entry=6)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
56      ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb)
(gdb)
(gdb) bt
#0  0x00007fffeeec8cc9 in __GI_raise (sig=sig@entry=6)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x00007fffeeecc0d8 in __GI_abort () at abort.c:89
#2  0x00007ffff7ec0202 in base::debug::BreakDebugger() ()
   from /usr/local/google/home/ukai/src/chromium-git/src/out.0/Release/./libbase.so
#3  0x00000000000000c8 in ?? ()
#4  0x00007ffff7ee175a in logging::LogMessage::~LogMessage() ()
   from /usr/local/google/home/ukai/src/chromium-git/src/out.0/Release/./libbase.so
#5  0x000024b18bffb300 in ?? ()
#6  0x000024b186e06d38 in ?? ()
#7  0x00007fffffffad98 in ?? ()
#8  0x00007ffff7f6b201 in tracked_objects::TaskStopwatch::Stop() ()
   from /usr/local/google/home/ukai/src/chromium-git/src/out.0/Release/./libbase.so
#9  0x36363a393336365b in ?? ()
#10 0x2f383133303a3933 in ?? ()
#11 0x463a343231323431 in ?? ()
#12 0x64656d3a4c415441 in ?? ()
#13 0x635f6265775f6169 in ?? ()
#14 0x5f73746e65746e6f in ?? ()
#15 0x726576726573626f in ?? ()
---Type <return> to continue, or q <return> to quit---
#16 0x293831322863632e in ?? ()
#17 0x206b63656843205d in ?? ()
#18 0x203a64656c696166 in ?? ()
#19 0x6e69663a3a647473 in ?? ()
#20 0x79616c702a282864 in ?? ()
#21 0x5b2970616d5f7265 in ?? ()
#22 0x74737269662e6469 in ?? ()
#23 0x286e696765622e5d in ?? ()
#24 0x616c702a28202c29 in ?? ()
#25 0x2970616d5f726579 in ?? ()
#26 0x737269662e64695b in ?? ()
#27 0x2928646e652e5d74 in ?? ()
#28 0x6365732e6469202c in ?? ()
#29 0x203d3d2029646e6f in ?? ()
#30 0x726579616c702a28 in ?? ()
#31 0x64695b2970616d5f in ?? ()
#32 0x2e5d74737269662e in ?? ()
#33 0x0a202e2928646e65 in ?? ()
#34 0x00007fffffffa660 in ?? ()
#35 0x00007fff00000001 in ?? ()
#36 0x000024b18304dcf0 in ?? ()
#37 0x000024b1858ef330 in ?? ()
#38 0x0000000000000000 in ?? ()


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https://chromium.googlesource.com/chromium/src/+/88c24007f6dc13d7e9e6b249e734ba5b668e8023