Wasted vector capacity in various DisplayList related code paths
Created attachment 425433 [details] Patch
This is a first cut. DrawGlyphs could be rewritten to allocate only as much space as is required. ItemBuffers could be shrunk.
Created attachment 425437 [details] Patch
Created attachment 425440 [details] Patch
https://trac.webkit.org/changeset/275639/webkit
<rdar://problem/76369458>