Move SkAtomics.h to private.

include/private/SkSemaphore.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkSemaphore_DEFINED
 #define SkSemaphore_DEFINED
 
 #include "SkTypes.h"
-#include "SkAtomics.h"
+#include "../private/SkAtomics.h"
 #include "../private/SkOncePtr.h"
 
 struct SkBaseSemaphore {
 
     // Increment the counter by 1.
     // This is a specialization for supporting SkMutex.
     void signal() {
         // Since this fetches the value before the add, 0 indicates that this thread is running and
         // no threads are waiting, -1 and below means that threads are waiting, but only signal 1
         // thread to run.
@@ skipping 54 matching lines @@
 
     void wait();
 
     void signal(int n = 1);
 
 private:
     SkBaseSemaphore fBaseSemaphore;
 };
 
 #endif//SkSemaphore_DEFINED