Move SkTypeface to sk_sp.

include/core/SkRefCnt.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkRefCnt_DEFINED
 #define SkRefCnt_DEFINED
 
@@ skipping 312 matching lines @@
     sk_sp<T>& operator=(sk_sp<T>&& that) {
         this->reset(that.release());
         return *this;
     }
     template <typename U, typename = skstd::enable_if_t<std::is_convertible<U*, T*>::value>>
     sk_sp<T>& operator=(sk_sp<U>&& that) {
         this->reset(that.release());
         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();
     }
 
     // MSVC 2013 does not work correctly with explicit operator bool.
     // https://chromium-cpp.appspot.com/#core-blacklist
     // When explicit operator bool can be used, remove operator! and operator unspecified_bool_type.
     //explicit operator bool() const { return this->get() != nullptr; }
     operator unspecified_bool_type() const { return this->get() ? &sk_sp::fPtr : nullptr; }
     bool operator!() const { return this->get() == nullptr; }
@@ skipping 116 matching lines @@
  *
  *  This function may be helpful while we convert callers from ptr-based to sk_sp-based parameters.
  */
 template <typename T> sk_sp<T> sk_ref_sp(T* obj) {
     return sk_sp<T>(SkSafeRef(obj));
 }
 
 #endif
 
 #endif