Update from https://crrev.com/327068

base/threading/platform_thread_linux.cc

Index: base/threading/platform_thread_linux.cc
diff --git a/base/threading/platform_thread_linux.cc b/base/threading/platform_thread_linux.cc
index 623a3dee678352aaf8a61b402c431a1727aa2fd9..b72fb5bb24b499bc1cac4faf72ac99b7b8be5c28 100644
--- a/base/threading/platform_thread_linux.cc
+++ b/base/threading/platform_thread_linux.cc
@@ -31,22 +31,42 @@ const struct sched_param kRealTimePrio = {8};
 }  // 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