Introduce PlatformThread::Detach

base/threading/platform_thread_posix.cc

Index: base/threading/platform_thread_posix.cc
diff --git a/base/threading/platform_thread_posix.cc b/base/threading/platform_thread_posix.cc
index d8bcf923a2bde1b50847271313e47f367c6955dc..2321b3cd49df64bbb352bc4cfd20994db691a099 100644
--- a/base/threading/platform_thread_posix.cc
+++ b/base/threading/platform_thread_posix.cc
@@ -209,6 +209,11 @@ void PlatformThread::Join(PlatformThreadHandle thread_handle) {
   CHECK_EQ(0, pthread_join(thread_handle.platform_handle(), NULL));
 }
 
+// static
+void PlatformThread::Detach(PlatformThreadHandle thread_handle) {
+  CHECK_EQ(0, pthread_detach(thread_handle.platform_handle()));
+}
+
 // Mac has its own Set/GetCurrentThreadPriority() implementations.
 #if !defined(OS_MACOSX)