remove docs for getFontBounds

Bug: skia:
Change-Id: Ic458e0feafc4fbebfc4db96c07e733b13b16c51a
Reviewed-on: https://skia-review.googlesource.com/c/174501
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed