Bot: https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win7?numbuilds=100

First failure build: https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win7/builds/56328

Output:
-----
20:18:35.343 4580 worker/6 webaudio/BiquadFilter/tail-time-lowpass.html crashed, (stderr lines):
20:18:35.343 4580   
20:18:35.344 4580   
20:18:35.344 4580   #
20:18:35.344 4580   # Fatal error in ../../v8/src/runtime/runtime-internal.cc, line 321
20:18:35.344 4580   # Check failed: size <= kMaxRegularHeapObjectSize.
20:18:35.344 4580   #
20:18:35.344 4580   Backtrace:
20:18:35.344 4580   	base::debug::StackTrace::StackTrace [0x01FD29F7+55]
20:18:35.344 4580   	base::debug::StackTrace::StackTrace [0x01FE68CA+10]
20:18:35.344 4580   	V8_Fatal [0x02B2F4B1+81]
20:18:35.344 4580   	v8::internal::Runtime_AllocateInNewSpace [0x01D7AB66+230]
20:18:35.350 4224 [10733/11910] webaudio/BiquadFilter/tail-time-lowpass.html failed unexpectedly (renderer crashed)
20:18:35.345 4580 worker/6 killing primary driver
20:18:35.345 4580 worker/6 killing secondary driver
20:18:35.345 4580 worker/6 webaudio/BiquadFilter/tail-time-lowpass.html failed:
20:18:35.345 4580 worker/6  renderer crashed
20:18:35.345 4580 worker/6 killing secondary driver
------

In the blamelist, the V8 roll[1] is the main suspect, and in that changelog[2] in particular the turbofan CLs looks suspicious.

[1] https://chromium.googlesource.com/chromium/src/+/3992a39b9192800cb552cfd0fb710cbb7211b1e5
[2] https://chromium.googlesource.com/v8/v8/+log/991ca91f..cd37d51d