Remove use of legacy SkFontMgr factories.

skia/ext/fontmgr_default_linux.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "skia/ext/fontmgr_default_linux.h"
 
 #include "third_party/skia/include/ports/SkFontConfigInterface.h"
 #include "third_party/skia/include/ports/SkFontMgr.h"
 #include "third_party/skia/include/ports/SkFontMgr_FontConfigInterface.h"
 
 namespace {
 // This is a purposefully leaky pointer that has ownership of the FontMgr.
 SkFontMgr* g_default_fontmgr;
 }  // namespace
 
-void SetDefaultSkiaFactory(SkFontMgr* fontmgr) {
-  g_default_fontmgr = fontmgr;
+void SetDefaultSkiaFactory(sk_sp<SkFontMgr> fontmgr) {
+  SkASSERT(g_default_fontmgr == nullptr);
+  g_default_fontmgr = fontmgr.release();
 }
 
-SK_API SkFontMgr* SkFontMgr::Factory() {
+SK_API sk_sp<SkFontMgr> SkFontMgr::Factory() {
   if (g_default_fontmgr) {
-    return SkRef(g_default_fontmgr);
+    return sk_ref_sp(g_default_fontmgr);
   }
   sk_sp<SkFontConfigInterface> fci(SkFontConfigInterface::RefGlobal());
   return fci ? SkFontMgr_New_FCI(std::move(fci)) : nullptr;
 }