Abandon onDrawText and its variants, turn everything into textblobs

Follow-ups assuming this sticks:
- remove client overrides, so we can remove the (empty) base class virtuals
- mark as obsolete the .skp enums for these entrypoints, and note date
- remove glyphrunlist helpers that now may not have any callers
- remove DrawCommands related to these entrypoints

Bug: skia:
Change-Id: I44b4e6ef3bee61911e77b9b2ab73f82c0817536a
Reviewed-on: https://skia-review.googlesource.com/c/175240
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Reviewed-by: Herb Derby <herb@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
22 files changed