Chrome Version: 55.0.2883.103
Chrome OS Version: 8872.73.0
Chrome OS Platform: elm

Steps To Reproduce:
Unknown.  
Issue from Feedback report: https://feedback.corp.google.com/product/208/neutron?lView=rd&lReport=52724907414

Expected Result:
Memory allocations succeed.  Tabs don't Crash.

Actual Result:
Tab crashed, UI log contains many messages like this (with various sizes):
[1:6:0204/200651:FATAL:memory.cc(22)] Out of memory. size=4194304

There is no indication what is running out of memory, or why.
There are no associated crash reports, nor backtraces in the feedback log.

How frequently does this problem reproduce? (Always, sometimes, hard to
reproduce?)

Unknown.

What is the impact to the user, and is there a workaround? If so, what is
it?

Tab crash.

Please provide any additional information below. Attach a screen shot or
log if possible.

There are plenty of physical memory available, but the virtual memory size of the browser process is approaching 4GB, so no more memory can be mapped:

top - 20:08:14 up 34 days,  9:01,  0 users,  load average: 2.66, 2.19, 2.14
Threads: 384 total,   3 running, 381 sleeping,   0 stopped,   0 zombie
%Cpu(s): 39.4 us, 11.4 sy,  0.2 ni, 48.9 id,  0.0 wa,  0.0 hi,  0.1 si,  0.0 st
KiB Mem:   4033088 total,  3002108 used,  1030980 free,    53772 buffers
KiB Swap:  3938560 total,   729392 used,  3209168 free.  1178448 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND
14534 chronos   12  -8 3952316 557548  62380 R 59.3 13.8 327:00.95 chrome

So I think there is some address space leak.