Simplify mask handling in SkRemoteGlyphCache

I'm only handling the processGlyphRunForMask in this CL, and I
am leaving processGlyphRunForPaths and maybeProcessGlyphRunForDFT
alone. I don't want to have to think about the Fallback code path
right now.

This should not be much of a problem because addGlyph exits early
if the glyph is already processed.

Change-Id: I78886ef87e2fbc3b9bfcb98101401138873bee37
Reviewed-on: https://skia-review.googlesource.com/c/190421
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Khushal Sagar <khushalsagar@chromium.org>
3 files changed