Adding trace markers in performance-critical functions.
Primary areas of interest are command buffer processing
and cleanup and memory mapping.

Bug: b/156403378
Change-Id: Icba53024771711d79f7eee7085bf4dae0e033e63
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2002689Reviewed-by: Charlie Lao <cclao@google.com>
Reviewed-by: Tobin Ehlis <tobine@google.com>
Commit-Queue: Tobin Ehlis <tobine@google.com>