Skia gold in pdfium

Backwards compatible with current pdfium recipe, so when this lands all
builds will run skia gold tests, alongside the current non-gold tests.
Gold failures will not fail the step or build.

Changed out optparse to argparse since optparse is now deprecated.

Bug: pdfium:1642
Change-Id: Ie38dcf45e526c81aae2179ca62c672ce8f38a6a1
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/77930
Commit-Queue: Stephanie Kim <kimstephanie@google.com>
Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
diff --git a/.gitignore b/.gitignore
index 2acea3e..af0aa39 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,6 +21,7 @@
 /tools/clang
 /tools/code_coverage
 /tools/memory
+/tools/skia_goldctl
 /v8
 /xcodebuild
 .DS_Store