It turned out that ApplyDXArray() is need to apply advance width
adjustments after justification, so we can't just bypass it.

So I just copied GenericSalLayout::ApplyDXArray() and stripped it of
ICUism so it does not break with HarfBuzz, but I had to make
m_GlyphItems non-private, so I'm not sure this is the right approach.

Change-Id: I66d647c3590fdf912c39d0cf23ac72bcc7ca72c9