base/threading: measure event wait times

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 44b691c1d638bd4fde69dbbe5b83adfc6f63092e..8e3f365c71f4a4464a428f68918f54ee2b09a7d0 100644
--- a/base/threading/platform_thread_posix.cc
+++ b/base/threading/platform_thread_posix.cc
@@ -13,6 +13,7 @@
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/profiler/scoped_tracker.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/platform_thread_internal_posix.h"
 #include "base/threading/thread_id_name_manager.h"
@@ -126,8 +127,13 @@ bool CreateThread(size_t stack_size, bool joinable,
 
   // Don't let this call complete until the thread id
   // is set in the handle.
-  if (success)
+  if (success) {
+    // TODO(toyoshim): Remove this after a few days (crbug.com/495097)
+    tracked_objects::ScopedTracker tracking_profile(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "495097 pthread_create and handle_set.Wait"));
     params.handle_set.Wait();
+  }
   CHECK_EQ(handle, thread_handle->platform_handle());
 
   return success;