Rearrange SkRecord with small N in mind

Rearrange SkRecord with small N in mind

This rearranges the record pointers and types so they can go in a single array, then preallocates some space for them and for the SkVarAlloc.

picture_overhead_draw bench drops from ~1000ns to 500-600ns, with no effect on picture_overhead_nodraw.

I don't see any significant effect on large picture recording times from our .skps.

BUG=chromium:470553

Committed: https://skia.googlesource.com/skia/+/e2dd9408cd711777afaa9410427fb0d761ab004a

Review URL: https://codereview.chromium.org/1061783002