base/threading: restrict to set only current thread priority

base/threading/platform_thread_mac.mm

 // 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.
 
 #include "base/threading/platform_thread.h"
 
 #import <Foundation/Foundation.h>
 #include <mach/mach.h>
 #include <mach/mach_time.h>
 #include <mach/thread_policy.h>
@@ skipping 137 matching lines @@
                         reinterpret_cast<thread_policy_t>(&time_constraints),
                         THREAD_TIME_CONSTRAINT_POLICY_COUNT);
   MACH_DVLOG_IF(1, result != KERN_SUCCESS, result) << "thread_policy_set";
 
   return;
 }
 
 }  // anonymous namespace
 
 // static
-void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
-                                       ThreadPriority priority) {
+void PlatformThread::SetCurrentThreadPriority(ThreadPriority priority) {
   // Convert from pthread_t to mach thread identifier.
-  mach_port_t mach_thread_id = pthread_mach_thread_np(handle.platform_handle());
+  mach_port_t mach_thread_id =
+      pthread_mach_thread_np(PlatformThread::CurrentHandle().platform_handle());
 
   switch (priority) {
     case ThreadPriority::NORMAL:
       SetPriorityNormal(mach_thread_id);
       break;
     case ThreadPriority::REALTIME_AUDIO:
       SetPriorityRealtimeAudio(mach_thread_id);
       break;
     default:
       NOTREACHED() << "Unknown priority.";
       break;
   }
 }
 
 // static
-ThreadPriority PlatformThread::GetThreadPriority(PlatformThreadHandle handle) {
+ThreadPriority PlatformThread::GetCurrentThreadPriority() {
   NOTIMPLEMENTED();
   return ThreadPriority::NORMAL;
 }
 
 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
 #if defined(OS_IOS)
   return 0;
 #else
   // The Mac OS X default for a pthread stack size is 512kB.
   // Libc-594.1.4/pthreads/pthread.c's pthread_attr_init uses
@@ skipping 26 matching lines @@
 #endif
 }
 
 void InitOnThread() {
 }
 
 void TerminateOnThread() {
 }
 
 }  // namespace base