Revert "Try capturing incorrect re-entrancy into DWriteFontProxy"

This reverts e630455cf22a85822e681f0c84134193aed73433.

The detection mechanism did not detect any crashes of this kind.  While
it's still very likely that the crashes are caused by Mojo sync calls
reentrancy issues, the particular theory of this change did not seem to
match what's going on. We should perhaps try to capture the re-entrancy
of font calls at the Mojo level, or move the font calls to a separate
blocking thread to avoid interference with other Mojo calls.

Bug: 561873
Change-Id: If0a1ce3b20fdf1f12afe1440db5b7989659a5e47
Reviewed-on: https://chromium-review.googlesource.com/c/1378141
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616976}
4 files changed