Use #if insteadof #ifdef DYNAMIC_ANNOTATIONS_ENABLED. It's always defined, just to 0 or 1.

src/core/SkOnce.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkOnce_DEFINED
 #define SkOnce_DEFINED
 
@@ skipping 106 matching lines @@
         release_barrier();
         *done = true;
     }
 }
 
 // We nabbed this code from the dynamic_annotations library, and in their honor
 // we check the same define.  If you find yourself wanting more than just
 // ANNOTATE_BENIGN_RACE, it might make sense to pull that in as a dependency
 // rather than continue to reproduce it here.
 
-#ifdef DYNAMIC_ANNOTATIONS_ENABLED
+#if DYNAMIC_ANNOTATIONS_ENABLED
 // TSAN provides this hook to supress a known-safe apparent race.
 extern "C" {
 void AnnotateBenignRace(const char* file, int line, const volatile void* mem, const char* desc);
 }
 #define ANNOTATE_BENIGN_RACE(mem, desc) AnnotateBenignRace(__FILE__, __LINE__, mem, desc)
 #else
 #define ANNOTATE_BENIGN_RACE(mem, desc)
 #endif
 
 // This is our fast path, called all the time.  We do really want it to be inlined.
@@ skipping 13 matching lines @@
     // The release barrier in sk_once_slow guaranteed that *done = true
     // happens after once(arg), so by syncing to *done = true here we're
     // forcing ourselves to also wait until the effects of once(arg) are readble.
     acquire_barrier();
 }
 
 #undef ANNOTATE_BENIGN_RACE
 
 
 #endif  // SkOnce_DEFINED