max glyph dimension == 0 means don't fallback

Specific case for this fuzz.
Assume that the font size is 0.
If the matrix is perspective then, we draw in paths. Drawing with paths
assumes a font size of 64, so glyphs have size. The glyph in question is
ARGB, so this will be drawn as fallback. The max glyph dimension, which is 13,
is multiplied by the strike-to-source ratio, which is 0 resulting in a
maxSourceGlyphDimension of 0.

Returning immediately from processARGBFallback when maxSourceGlyphDimension
equals 0 is the correct thing to do for all cases because no pixels will change.

BUG=oss-fuzz:15052

Change-Id: I8809a08f011c93a0f7f47422b594c8264a8a9326
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/217497
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
1 file changed