Modernize and trim down SkOnce.

src/core/SkOpts.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkHalf.h"
 #include "SkOnce.h"
 #include "SkOpts.h"
@@ skipping 119 matching lines @@
         }
 
     #elif !defined(SK_ARM_HAS_NEON)      && \
            defined(SK_CPU_ARM32)         && \
            defined(SK_BUILD_FOR_ANDROID) && \
           !defined(SK_BUILD_FOR_ANDROID_FRAMEWORK)
         if (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) { Init_neon(); }
     #endif
     }
 
-    SK_DECLARE_STATIC_ONCE(gInitOnce);
-    void Init() { SkOnce(&gInitOnce, init); }
+    void Init() {
+        static SkOnce once;
+        once(init);
+    }
 
 #if SK_ALLOW_STATIC_GLOBAL_INITIALIZERS
     static struct AutoInit {
         AutoInit() { Init(); }
     } gAutoInit;
 #endif
 }