Fix typeface GMs to draw or skip
Fix typeface GMs to draw or skip

Before this change the typeface_styling GM would draw an empty canvas if
the default SkFontMgr could not load a 'ttf' font. Instead of drawing
nothing, attempt to draw an 'A' in the default available font.

Before this change the typeface_rendering GMs would draw an empty canvas
if the default SkFontMgr could not load a 'ttf' font. Instea of drawing
nothing, skip the test instead.

Change-Id: I15b3c5aae7ac0d2e8f0291456a84291768b009a0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/438276
Reviewed-by: Robert Phillips <95e8ac5504948c7bf91b22c16a8dbb7ae7c66bfd@google.com>
Reviewed-by: Mike Reed <f5cabf8735907151a446812c9875d6c0c712d847@google.com>
Commit-Queue: Ben Wagner <53965154ffeecc4a10886eab9259e95965f2979a@google.com>

aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia