Clean up SkString reference counting a bit.

This reverts commit 01f8e41c1368bfd60d3f011cb5aa9cc478799e63, and then
works around whatever issues were seen on Ubuntu 14 by continuing the
clean up.

Change-Id: I3523b12c83e4efef01a8142c00cde4e3e12189fa
Reviewed-on: https://skia-review.googlesource.com/55761
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
2 files changed