Delete unused corpus test expectations

Gets rid of unused corpus test expectations. These expectations do not
match any current output, and so tests are just falling back to a less
specific expectation anyway.

Rather than being deleted entirely, some Mac-specific expectations have
been renamed to AGG Mac-specific expectations instead. This will help
ensure Skia configurations do not try to match against them.

Since all the changes are either deletions or renames, it shouldn't be
necessary to review the content of each individual image.

This change requires adding support for "_agg" expectations to the
presubmit. This change also tries to converge the presubmit in this
repository with PDFium's similar presubmit.

Bug: pdfium:1987
Change-Id: I1458ca697715b4e2c1fc127ca6ad598a7be39309
Reviewed-by: Nigi <>
630 files changed