Purge ImplementsThreadSafeReferenceCounting() from the codebase now that Task is dead.

ppapi/native_client/src/include/ref_counted.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NATIVE_CLIENT_SRC_INCLUDE_REF_COUNTED_H_
 #define NATIVE_CLIENT_SRC_INCLUDE_REF_COUNTED_H_
 
 #include "native_client/src/shared/platform/nacl_sync_checked.h"
 
 namespace nacl {
 
 namespace subtle {
 
 class RefCountedBase {
  public:
-  static bool ImplementsThreadSafeReferenceCounting() { return true; }
-
   bool HasOneRef() const {
     nacl::ScopedNaClMutexLock ml(&mu_);
     return (ref_count_ == 1);
   }
 
  protected:
   RefCountedBase() : ref_count_(0) {
     NaClXMutexCtor(&mu_);
   }
   ~RefCountedBase() {
@@ skipping 198 matching lines @@
 };
 
 // Handy utility for creating a scoped_refptr<T> out of a T* explicitly without
 // having to retype all the template arguments
 template <typename T>
 scoped_refptr<T> make_scoped_refptr(T* t) {
   return scoped_refptr<T>(t);
 }
 
 #endif  // NATIVE_CLIENT_SRC_INCLUDE_REF_COUNTED_H_