Remove getGlyphMetrics from the interface

The shared Renderer/GPU code only uses the bulk API now.

Change-Id: I04f4f75c94e599a961e10c48a72248bc2624c902
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/223800
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
6 files changed