GitLab

- Add kBackForwardCacheMemoryControl feature which can be controlled via
  experiment.
- Introduce "memory_threshold_for_back_forward_cache_in_mb" to control the
  factor via experiment.

Bug: 1017090
Change-Id: I44d95da16f4023ea5b8ad890dd539784c74006c6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1875091Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Sreeja Kamishetty <sreejakshetty@chromium.org>
Cr-Commit-Position: refs/heads/master@{#718605}