Update fontMgr to take list of bcp47 language tags.

This will enable clients to pass more than one bcp47 tag to ensure
that the most appropriate font is selected.

BUG=chromium:422180

Review URL: https://codereview.chromium.org/670243002
Revert of Delete unused method aliases and texture flag. (patchset #1 id:1 of https://codereview.chromium.org/672753002/)

Reason for revert:
Need to remove one more reference to this in blink before relanding.

Original issue's description:
> Delete unused method aliases and texture flag.
>
> Committed: https://skia.googlesource.com/skia/+/7fdffe41494cbd78a8ee2a6ef0509e46ec77039f

TBR=robertphillips@google.com
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/671203002
Add SkMaskCache

BUG=skia:

Review URL: https://codereview.chromium.org/670063004
Rename Nexus9 expectations

BUG=skia:3047
TBR=djsollen

Review URL: https://codereview.chromium.org/652003003