add SkAutoTUnref

[Steve VanDeBogart, 2011-02-24 23:04:54]

LGTM, with the suggestions below.

http://codereview.appspot.com/4233041/diff/1/include/core/SkRefCnt.h
File include/core/SkRefCnt.h (right):

http://codereview.appspot.com/4233041/diff/1/include/core/SkRefCnt.h#newcode76
include/core/SkRefCnt.h:76: class SkAutoUnref : SkNoncopyable {
Instead of having two copies, you can typedef SkAutoUnref SkAutoTUnref<SkRefCnt>

http://codereview.appspot.com/4233041/diff/1/include/core/SkRefCnt.h#newcode93
include/core/SkRefCnt.h:93: bool unref();
SkAutoUnref and SkAutoTUnref have different behavior, you may want to note that.

http://codereview.appspot.com/4233041/diff/1/include/core/SkRefCnt.h#newcode109
include/core/SkRefCnt.h:109: SkAutoTUnref(T* obj) : fObj(obj) {}
SkRefCnt.h is included in a lot of places, so I would put all the
implementations in the .cpp file.

http://codereview.appspot.com/4233041/diff/1/tests/UtilsTest.cpp
File tests/UtilsTest.cpp (right):

http://codereview.appspot.com/4233041/diff/1/tests/UtilsTest.cpp#newcode60
tests/UtilsTest.cpp:60: 
You can test that the auto unref works with something like:

REPORTER_ASSERT(reporter, 2 == ref.getRefCnt())
{
    SkAutoTUnref<RefClass> tmp2(&ref)
    REPORTER_ASSERT(reporter, 2 == ref.getRefCnt())
}
REPORTER_ASSERT(reporter, 1 == ref.getRefCnt())

[reed1, 2011-02-25 13:34:05]

Combined the two classes now.

Removed the ref/unref apis, as they were a little confusing (especially
unref()), and they were unused afaik. If we discover they are used somewhere,
they are easy to put back.

[Steve VanDeBogart, 2011-02-25 18:06:37]

LGTM.

You made me dig up why I suggested keeping the implementation in the .cpp file:
https://sites.google.com/a/chromium.org/dev/developers/coding-style/cpp-dos-a...
The biggest point being that the compiler is probably including a non-inlined
version of those methods in many .o files, which slows link time.