High percentage of Missed User Stacks profile tool with chrome browser

When running chrome (web browser built form sources with support for profiling/perf to do stack unwinding etc ) on ubuntu18.04.1 LTS and kernel 4.15.0-44-generic x86_64
sudo /usr/share/bcc/tools/profile -f -F 1000 -p PID-of-chrome > chrome.stacks
Then loading and starting the jetstream https://browserbench.org/JetStream/ javascript benchmark (clicking on test) and running for 1 iteration prior to CTRL-C of the profile
I get a large percentage - typically around 20% and sometimes as high as 56% of total stacks as "Missed User Stack". Im running on a standard lenovo desktop 4 real cores.

NOTE: perf does not suffer from this problem. I've tried running with/without perf jit symbol support. altering the --stack-storage-size and they don't make a difference. I use top to determine the correct TGID to use for -p. Such a large error makes any generated flamegraphs pretty unusable. Have I missed anything obvious here?

Start by reproducing the reported command with /usr/share/bcc/tools/profile against Chrome while running the JetStream benchmark, then compare its output with perf. Investigate the source and existing tests for the profile tool to identify why user stacks are missed; done means the cause is explained and the profiling output is corrected or the limitation is clearly documented.

Written by the indexing model from the issue text.