Remove profiler_event proto

Now that the task profiler has been removed, the proto for sending
events is not needed either.

Bug: 739505
Change-Id: Ic3d8b509467618427763af477d44ee7b48a573d9
Reviewed-on: https://chromium-review.googlesource.com/681576
Reviewed-by: Steven Holte <[email protected]>
Commit-Queue: Brett Wilson <[email protected]>
Cr-Commit-Position: refs/heads/master@{#504542}
3 files changed