Update format_custom_format.pdf expectations

Updates format_custom_format.pdf expectations, generating a new
expectation for AGG on Mac, and reusing the expectation for Skia on
Windows for all platforms.

Bug: pdfium:1855
Change-Id: I9d8355028aacdf9193fd69dc0f60704a26f6c62b
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium_tests/+/104890
Reviewed-by: Nigi <nigi@chromium.org>

fx/form/format_custom_format_expected_mac.pdf.0.png

diff --git a/fx/form/format_custom_format_expected_mac.pdf.0.png b/fx/form/format_custom_format_expected_mac.pdf.0.png
new file mode 100644
index 0000000..6f9509d
--- /dev/null
+++ b/fx/form/format_custom_format_expected_mac.pdf.0.png
Binary files differ

fx/form/format_custom_format_expected_skia.pdf.0.png

diff --git a/fx/form/format_custom_format_expected_skia.pdf.0.png b/fx/form/format_custom_format_expected_skia.pdf.0.png
index d4ec598..2d551ca 100644
--- a/fx/form/format_custom_format_expected_skia.pdf.0.png
+++ b/fx/form/format_custom_format_expected_skia.pdf.0.png
Binary files differ

fx/form/format_custom_format_expected_skia_win.pdf.0.png

diff --git a/fx/form/format_custom_format_expected_skia_win.pdf.0.png b/fx/form/format_custom_format_expected_skia_win.pdf.0.png
deleted file mode 100644
index 2d551ca..0000000
--- a/fx/form/format_custom_format_expected_skia_win.pdf.0.png
+++ /dev/null
Binary files differ