SkPDF: rasterize bitmap glyphs at 64pt, not em-size

Motivation: em-size is often results in huge bitmaps for each glyph
(e.g. 2556x2406 rgba pixels).

Define SK_PDF_BITMAP_GLYPH_RASTER_SIZE to 0 to get previous behaviour.

Define SK_PDF_BITMAP_GLYPH_RASTER_SIZE to a positive value to rasterize
at that font size rather than 64pt.

Bug: b/141094460
Bug: chromium:921585
Change-Id: I4523e512ec149cf02c985eb83f2e640a2c680d3a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/245160
Commit-Queue: Hal Canary <halcanary@skia.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
1 file changed