Revert of teach TSAN about SkSpinlock, SkRefCnt, and SkOnce

include/core/SkRefCnt.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkRefCnt_DEFINED
@@ skipping 89 matching lines @@
      */
     void internal_dispose_restore_refcnt_to_1() const {
 #ifdef SK_DEBUG
         SkASSERT(0 == fRefCnt);
         fRefCnt = 1;
 #endif
     }
 
 private:
     // OK for use in asserts, but not much else.
-    int32_t unsafeGetRefCnt() const { return SK_ANNOTATE_UNPROTECTED_READ(fRefCnt); }
+    int32_t unsafeGetRefCnt() { return SK_ANNOTATE_UNPROTECTED_READ(fRefCnt); }
 
     /**
      *  Called when the ref count goes to 0.
      */
     virtual void internal_dispose() const {
         this->internal_dispose_restore_refcnt_to_1();
         SkDELETE(this);
     }
 
     // The following friends are those which override internal_dispose()
@@ skipping 168 matching lines @@
     typedef T* SkRefPtr::*unspecified_bool_type;
     operator unspecified_bool_type() const {
         return fObj ? &SkRefPtr::fObj : NULL;
     }
 
 private:
     T* fObj;
 };
 
 #endif