Add full SetThreadPriority support to Windows.

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..5f9e83336c48b1ed95d860a135fd78f071403a80 100644
--- a/base/threading/platform_thread_linux.cc
+++ b/base/threading/platform_thread_linux.cc
@@ -47,6 +47,23 @@ bool HandleSetThreadPriorityForPlatform(PlatformThreadHandle handle,
 #endif
 }
 
+bool HandleGetThreadPriorityForPlatform(PlatformThreadHandle handle,
+                                        ThreadPriority* priority) {
+#if !defined(OS_NACL)
+  // Mirrors HandleSetThreadPriorityForPlatform()'s implementation.
+  int maybe_sched_rr = 0;
+  struct sched_param maybe_realtime_prio = {0};
+  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 = kThreadPriority_RealtimeAudio;
+    return true;
+  }
+#endif
+  return false;
+}
+
 }  // namespace internal
 
 // static