Require SK_DECLARE_STATIC_LAZY_PTR is used in global scope.

src/core/SkLazyPtr.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkLazyPtr_DEFINED
 #define SkLazyPtr_DEFINED
 
@@ skipping 29 matching lines @@
  *
  *
  *  You can think of SK_DECLARE_STATIC_LAZY_PTR as a cheaper specialization of
  *  SkOnce.  There is no mutex or extra storage used past the pointer itself.
  *  In debug mode, each lazy pointer will be cleaned up at process exit so we
  *  can check that we've not leaked or freed them early.
  *
  *  We may call Create more than once, but all threads will see the same pointer
  *  returned from get().  Any extra calls to Create will be cleaned up.
  *
- *  These macros must be used in a global or function scope, not as a class member.
+ *  These macros must be used in a global scope, not in function scope or as a class member.
  */
 
 #define SK_DECLARE_STATIC_LAZY_PTR(T, name, ...) \
-    static Private::SkLazyPtr<T, ##__VA_ARGS__> name
+    namespace {} static Private::SkLazyPtr<T, ##__VA_ARGS__> name
 
 #define SK_DECLARE_STATIC_LAZY_PTR_ARRAY(T, name, N, ...) \
-    static Private::SkLazyPtrArray<T, N, ##__VA_ARGS__> name
+    namespace {} static Private::SkLazyPtrArray<T, N, ##__VA_ARGS__> name
 
+// namespace {} forces these macros to only be legal in global scopes.  Chrome has thread-safety
+// problems with them in function-local statics because it uses -fno-threadsafe-statics, and even
+// in builds with threadsafe statics, those threadsafe statics are just unnecessary overhead.
 
 
 // Everything below here is private implementation details.  Don't touch, don't even look.
 
 #include "SkDynamicAnnotations.h"
 #include "SkThread.h"
 #include "SkThreadPriv.h"
 
 // See FIXME below.
 class SkFontConfigInterfaceDirect;
@@ skipping 80 matching lines @@
     }
 #endif
 
 private:
     void* fArray[N];
 };
 
 }  // namespace Private
 
 #endif//SkLazyPtr_DEFINED