Remove always-enabled flag kUsePaintRecordForImageSkia

This flag is enabled by default, not exposed in about://flags, and not
used in any experiments.

Additionally, this flag is queried in hot code. Removing the flag
eliminates the need to refactor the check out of the hot path.

Bug: 960913
Change-Id: Ida88f9c7b999eece39ea6bc434e041364819fda3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1601935
Commit-Queue: Collin Baker <collinbaker@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Malay Keshav <malaykeshav@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658250}
5 files changed