Update from https://crrev.com/327068

base/threading/platform_thread_linux.cc

 // 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"
 
 #include <errno.h>
 #include <sched.h>
 
 #include "base/lazy_instance.h"
@@ skipping 13 matching lines @@
 
 namespace internal {
 
 namespace {
 #if !defined(OS_NACL)
 const struct sched_param kRealTimePrio = {8};
 #endif
 }  // namespace
 
 const ThreadPriorityToNiceValuePair kThreadPriorityToNiceValueMap[4] = {
-    {kThreadPriority_RealtimeAudio, -10},
-    {kThreadPriority_Background, 10},
-    {kThreadPriority_Normal, 0},
-    {kThreadPriority_Display, -6},
+    {ThreadPriority::BACKGROUND, 10},
+    {ThreadPriority::NORMAL, 0},
+    {ThreadPriority::DISPLAY, -6},
+    {ThreadPriority::REALTIME_AUDIO, -10},
 };
 
-bool HandleSetThreadPriorityForPlatform(PlatformThreadHandle handle,
-                                        ThreadPriority priority) {
+bool SetThreadPriorityForPlatform(PlatformThreadHandle handle,
+                                  ThreadPriority priority) {
 #if !defined(OS_NACL)
-  return priority == kThreadPriority_RealtimeAudio &&
+  // TODO(gab): Assess the correctness of using |pthread_self()| below instead
+  // of |handle|. http://crbug.com/468793.
+  return priority == ThreadPriority::REALTIME_AUDIO  &&
          pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0;
 #else
   return false;
 #endif
 }
 
+bool GetThreadPriorityForPlatform(PlatformThreadHandle handle,
+                                  ThreadPriority* priority) {
+#if !defined(OS_NACL)
+  int maybe_sched_rr = 0;
+  struct sched_param maybe_realtime_prio = {0};
+  // TODO(gab): Assess the correctness of using |pthread_self()| below instead
+  // of |handle|. http://crbug.com/468793.
+  if (pthread_getschedparam(pthread_self(), &maybe_sched_rr,
+                            &maybe_realtime_prio) == 0 &&
+      maybe_sched_rr == SCHED_RR &&
+      maybe_realtime_prio.sched_priority == kRealTimePrio.sched_priority) {
+    *priority = ThreadPriority::REALTIME_AUDIO;
+    return true;
+  }
+#endif
+  return false;
+}
+
 }  // namespace internal
 
 // static
 void PlatformThread::SetName(const char* name) {
   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
   tracked_objects::ThreadData::InitializeThreadContext(name);
 
 #if !defined(OS_NACL)
   // On linux we can get the thread names to show up in the debugger by setting
   // the process name for the LWP.  We don't want to do this for the main
@@ skipping 24 matching lines @@
 #if !defined(THREAD_SANITIZER)
   return 0;
 #else
   // ThreadSanitizer bloats the stack heavily. Evidence has been that the
   // default stack size isn't enough for some browser tests.
   return 2 * (1 << 23);  // 2 times 8192K (the default stack size on Linux).
 #endif
 }
 
 }  // namespace base