Rename TestSize.cpp to SizeTest.cpp

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
2 files changed