Use SkGlyphRun directly in SkRemoteGlyphCache

Remove use of the text blob iterator shim in preparation to have
remote glyph cache and GPU share code.

Change-Id: Ib94c3ee22ae7305145bde72dd039354e7e204f93
Reviewed-on: https://skia-review.googlesource.com/148392
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
3 files changed