This extends instrumentation added in r30683 and r30768 to cover
the possibility that the root cause we're after is in optimized code.

This CL is intended to be reverted in a couple of days, but should
cause no harm while it's in the tree (we would crash anyway).

BUG=chromium:527994
LOG=n

Review URL: https://codereview.chromium.org/1348823003

Cr-Commit-Position: refs/heads/master@{#30819}