Use BigBuffer for SkBitmap mojom pixel data

This avoids large bitmaps yielding large messages, as BigBuffer falls
back onto shared memory beyond a certain size threshold.

Bug: 829659
Cq-Include-Trybots: luci.chromium.try:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win10_chromium_x64_rel_ng
Change-Id: I82f907144944f2e8ebea51264fc00afc171ce3bf
Reviewed-on: https://chromium-review.googlesource.com/1004598
Commit-Queue: Ken Rockot <rockot@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551254}
31 files changed