Tracing: Flag event emitted when no PostTask is possible

Perfetto can end up PostTasking in certain situations (like when
creating a TraceWriter, or wanting to commit a chunk of data);
while the taskqueue is locked this isn't possible so we need to
flag these events to enable Perfetto to avoid PostTasking
under these circumstances.

R=gab@chromium.org

Bug: 898597
Change-Id: I3e1e35ec9858203dbdc8ac8560cdedda45aafb6a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1531611
Commit-Queue: oysteine <oysteine@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#642668}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: c86bc635d8fd418b71a506f9e0444e36fc6c1eaa
1 file changed
tree: 65f8bd335afd68a05bd0500818a4e50128146ba0
  1. trace_event_common.h