Revert of Port uses of SkLazyPtr to SkOncePtr.

src/core/SkFontMgr.cpp

Index: src/core/SkFontMgr.cpp
diff --git a/src/core/SkFontMgr.cpp b/src/core/SkFontMgr.cpp
index 3190825c0fd4ca9d0bcd7378c877b21649ca1104..7c06690d2e297e0892cbeaf685e100c6e43fa974 100644
--- a/src/core/SkFontMgr.cpp
+++ b/src/core/SkFontMgr.cpp
@@ -7,7 +7,7 @@
 
 #include "SkFontDescriptor.h"
 #include "SkFontMgr.h"
-#include "SkOncePtr.h"
+#include "SkLazyPtr.h"
 #include "SkStream.h"
 #include "SkTypes.h"
 
@@ -158,10 +158,14 @@
     return this->onLegacyCreateTypeface(familyName, styleBits);
 }
 
-SK_DECLARE_STATIC_ONCE_PTR(SkFontMgr, singleton);
+// As a template argument this must have external linkage.
+SkFontMgr* sk_fontmgr_create_default() {
+    SkFontMgr* fm = SkFontMgr::Factory();
+    return fm ? fm : new SkEmptyFontMgr;
+}
+
+SK_DECLARE_STATIC_LAZY_PTR(SkFontMgr, singleton, sk_fontmgr_create_default);
+
 SkFontMgr* SkFontMgr::RefDefault() {
-    return SkRef(singleton.get([]{
-        SkFontMgr* fm = SkFontMgr::Factory();
-        return fm ? fm : new SkEmptyFontMgr;
-    }));
+    return SkRef(singleton.get());
 }