[skottie shaper] Fix consolidated fragment mode
[skottie shaper] Fix consolidated fragment mode

After [1], consolidated-mode shaping is running into issues because it
assumes there is only a single result fragment, positioned at the text
box origin.

We only need to add empty fragments in fragmented mode, since all
features requiring line index information will use
Shaper::Flags::kFragmentGlyphs.

[1] https://skia-review.googlesource.com/c/skia/+/588737

Change-Id: Idfd7cb34257524f4502059b708095c13d5c9d157
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/589476
Commit-Queue: Florin Malita <a8262bf13ea8c26821e91ea9bca6740a77c96dcd@google.com>
Reviewed-by: Ben Wagner <53965154ffeecc4a10886eab9259e95965f2979a@google.com>

google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia