It is the only file where Test is the prefix rather than the sufix.
This patch fixes that so it matches with the rest of the files
under tests/ directory.
And separate SkISize test into its own DEF_TEST().
BUG=None
TEST=make tests && out/Debug/tests
R=mtklein@google.com
Author: tfarina@chromium.org
Review URL: https://codereview.chromium.org/337783007
