[SPv175] Update test expectations

- Update bug numbers and comments

- Modify fast/multicol/border-radius-clipped-layer-expected.html to make it
  pass for both SPv1 and SPv175 (previously with one invisible pixel diff).

- Rebaseline svg/hixie/perf/007.svg

- enable virtual/prefer_compositing_to_lcd_text/compositing for flag-specific
  testing.

Bug: 771643
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: Ie56c6ea26672552594b7c83f0fc80252254daac3
Reviewed-on: https://chromium-review.googlesource.com/891426
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533605}
10 files changed