Remove skstd::is_convertible.

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
 
 #include "../private/SkTLogic.h"
 #include "SkTypes.h"
 #include <atomic>
 #include <functional>
 #include <memory>
+#include <type_traits>
 #include <utility>
 
 #define SK_SUPPORT_TRANSITION_TO_SP_INTERFACES
 
 /** \class SkRefCntBase
 
     SkRefCntBase is the base class for objects that may be shared by multiple
     objects. When an existing owner wants to share a reference, it calls ref().
     When an owner wants to release its reference, it calls unref(). When the
     shared object's reference count goes to zero as the result of an unref()
@@ skipping 238 matching lines @@
     using element_type = T;
 
     sk_sp() : fPtr(nullptr) {}
     sk_sp(std::nullptr_t) : fPtr(nullptr) {}
 
     /**
      *  Shares the underlying object by calling ref(), so that both the argument and the newly
      *  created sk_sp both have a reference to it.
      */
     sk_sp(const sk_sp<T>& that) : fPtr(SkSafeRef(that.get())) {}
-    template <typename U, typename = skstd::enable_if_t<skstd::is_convertible<U*, T*>::value>>
+    template <typename U, typename = skstd::enable_if_t<std::is_convertible<U*, T*>::value>>
     sk_sp(const sk_sp<U>& that) : fPtr(SkSafeRef(that.get())) {}
 
     /**
      *  Move the underlying object from the argument to the newly created sk_sp. Afterwards only
      *  the new sk_sp will have a reference to the object, and the argument will point to null.
      *  No call to ref() or unref() will be made.
      */
     sk_sp(sk_sp<T>&& that) : fPtr(that.release()) {}
-    template <typename U, typename = skstd::enable_if_t<skstd::is_convertible<U*, T*>::value>>
+    template <typename U, typename = skstd::enable_if_t<std::is_convertible<U*, T*>::value>>
     sk_sp(sk_sp<U>&& that) : fPtr(that.release()) {}
 
     /**
      *  Adopt the bare pointer into the newly created sk_sp.
      *  No call to ref() or unref() will be made.
      */
     explicit sk_sp(T* obj) : fPtr(obj) {}
 
     /**
      *  Calls unref() on the underlying object pointer.
      */
     ~sk_sp() {
         SkSafeUnref(fPtr);
         SkDEBUGCODE(fPtr = nullptr);
     }
 
     sk_sp<T>& operator=(std::nullptr_t) { this->reset(); return *this; }
 
     /**
      *  Shares the underlying object referenced by the argument by calling ref() on it. If this
      *  sk_sp previously had a reference to an object (i.e. not null) it will call unref() on that
      *  object.
      */
     sk_sp<T>& operator=(const sk_sp<T>& that) {
         this->reset(SkSafeRef(that.get()));
         return *this;
     }
-    template <typename U, typename = skstd::enable_if_t<skstd::is_convertible<U*, T*>::value>>
+    template <typename U, typename = skstd::enable_if_t<std::is_convertible<U*, T*>::value>>
     sk_sp<T>& operator=(const sk_sp<U>& that) {
         this->reset(SkSafeRef(that.get()));
         return *this;
     }
 
     /**
      *  Move the underlying object from the argument to the sk_sp. If the sk_sp previously held
      *  a reference to another object, unref() will be called on that object. No call to ref()
      *  will be made.
      */
     sk_sp<T>& operator=(sk_sp<T>&& that) {
         this->reset(that.release());
         return *this;
     }
-    template <typename U, typename = skstd::enable_if_t<skstd::is_convertible<U*, T*>::value>>
+    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 {
         SkASSERT(this->get() != nullptr);
         return *this->get();
     }
 
@@ skipping 122 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