Move SkTypeface to sk_sp.

include/core/SkRefCnt.h

Index: include/core/SkRefCnt.h
diff --git a/include/core/SkRefCnt.h b/include/core/SkRefCnt.h
index c45ed6bbf06f0d261f6efde6b696da538166b0dd..d3d05012dc1e286b76c03d75be145c7e65b38bf0 100644
--- a/include/core/SkRefCnt.h
+++ b/include/core/SkRefCnt.h
@@ -330,7 +330,7 @@ public:
         return *this;
     }
 
-    T& operator*() const {
+    skstd::add_lvalue_reference_t<T> operator*() const {

[reed1, 2016/05/01 18:53:52]

Is this change a necessary part of the "typeface" CL, or can it land separately?

[bungeman-skia, 2016/05/02 20:24:54]

No, I'll stick this in another CL, it got mixed up in here. This is what the stl
does (after some debate). The difference is that it works with void, so you can
create the type sk_sp<void>, which isn't particularly useful, but avoids certain
issues when writing generic template code.

         SkASSERT(this->get() != nullptr);
         return *this->get();
     }