Fix thread unsafe mutex initialization.

src/ports/SkMutex_pthread.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 SkMutex_pthread_DEFINED
 #define SkMutex_pthread_DEFINED
 
@@ skipping 71 matching lines @@
         default:
             SkDebugf("pthread error [%d] unknown\n", status);
             break;
         }
     }
 };
 
 #define SK_BASE_MUTEX_INIT { PTHREAD_MUTEX_INITIALIZER, SkDEBUGCODE(0) }
 
 // Using POD-style initialization prevents the generation of a static initializer.
+//
 // Without magic statics there are no thread safety guarantees on initialization
-// of local statics (even POD).
-// As a result, it is illegal to SK_DECLARE_STATIC_MUTEX in a function.
-#define SK_DECLARE_STATIC_MUTEX(name) \
-    static inline void SK_MACRO_APPEND_LINE(name)(){} \
-    static SkBaseMutex name = SK_BASE_MUTEX_INIT
+// of local statics (even POD). As a result, it is illegal to use
+// SK_DECLARE_STATIC_MUTEX in a function.
+//
+// Because SkBaseMutex is not a primitive, a static SkBaseMutex cannot be
+// initialized in a class with this macro.
+#define SK_DECLARE_STATIC_MUTEX(name) namespace {} static SkBaseMutex name = SK_BASE_MUTEX_INIT
 
 #endif