[perf_skottiewasm_lottieweb] Start tracking timings of drawn frames and count aborted frames

Adds the following new metrics:

* aborted_frames: These are the number of frames which have "main_frame_aborted" terminations in the chosen 25 samples.

* drawn_frame_max_us / drawn_frame_min_us / drawn_frame_avg_us: These metrics are similar to the existing "frame_*_us" metrics but are calculated using only drawn frames (frames terminated with missed_frame or submitted_frame).

Bug: skia:9237
Change-Id: Ib6ed29f7ae6a1f7b6660f231aad528fe7bb6f203
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/229419
Commit-Queue: Ravi Mistry <rmistry@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
9 files changed