lookup sent types using factory pointer

We can make tracking whether we've sent a type already a bit more
streamlined by avoiding this string copy, and while we're at it, using a
smaller unique key, the type factory pointer.

This doesn't change the wire protocol of how we send across flattenable
types... first as a name string, then each time after as a 24-bit int.
The factory pointers still never hit the wire, so this can continue to
work cross-process.

Change-Id: I1ee754971dc48d56b5d62561d8e83209f1e33728
Reviewed-on: https://skia-review.googlesource.com/c/168264
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
2 files changed