Improve DDLTileHelper

TileData now gets a pointer to the final surface
   This allows the tile to, once rendered, compose itself into
   the final surface

DDLTileHelper now stores the TileData in a dumb array
   SkTArray is overkill and, since TileData*s are being doled
   out to threads, we never want reallocation

Added DDLTileHelper::kickOffThreadedWork
   The old code only performed DDL creation in parallel. This
   entry point also replays the DDLs and composes them into the
   final surface in parallel

Change-Id: I66e02ef7f8291b4d402e22bee0ad3546e930609e
Reviewed-by: Greg Daniel <>
Commit-Queue: Robert Phillips <>
4 files changed