Use common path drawing code

Currently, there are two methods for drawing paths. The device metrics
version that uses the glyphs from the mask paths directly, and the common
path (font size 64) version that uses scaling to generate the paths.

This change removes the device metrics version. This is a very rare execution
path because, the font size needs to be < 132, but still generate a glyph with
dimensions > 256. I have only seen this in the wild once.

This change simplifies the code, and does not change the behavior very much.
There are only two GMs show big numerical changes. One has visible differences
(textblobmixedsizes), and the other is very slight visible difference(mixedtextblobs),
 but it is not wrong.

Change-Id: Ieb10cd73c81196c66be5f791d591471e15175917
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/249888
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
4 files changed