Obviously these are all currently function pointers of type T(*)(P) for various
T and P. In bench refactoring, I'm trying to register a function pointer of
type T(*)(), which can't be done as is (passing P=void doesn't work). This
also lets us register things like primitives, which is conceivable useful.
BUG=
R=reed@google.com, scroggo@google.com
Review URL: https://codereview.chromium.org/23453031
git-svn-id: http://skia.googlecode.com/svn/trunk@11082 2bbb7eff-a529-9590-31e7-b0007b416f81
