Load FreeType glyph bitmap before emboldening.

Load FreeType glyph bitmap before emboldening.

If a bitmap glyph was loaded with FT_LOAD_BITMAP_METRICS_ONLY then the
glyph must be re-loaded without this flag before accessing the bitmap.

BUG=chromium:725975

Change-Id: If5e5a6844e9c32238560135e141fea7f77ad7fac
Reviewed-on: https://skia-review.googlesource.com/20830
Reviewed-by: Herb Derby <herb@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>

Cherry-Pick: c3aef18419c1bb16951370e11758c7ef131fa10b
Approval: https://crbug.com/725975#c24