EDK: Move mutex.*, cond_var.*, and thread_annotations.h to //mojo/edk/util.

mojo/edk/system/waiter_unittest.cc

Index: mojo/edk/system/waiter_unittest.cc
diff --git a/mojo/edk/system/waiter_unittest.cc b/mojo/edk/system/waiter_unittest.cc
index faf89f83041699ba49ad7e41b18c70cf7b1582a4..9a344f5a1161739b856e3da51bd0829b7876412a 100644
--- a/mojo/edk/system/waiter_unittest.cc
+++ b/mojo/edk/system/waiter_unittest.cc
@@ -11,14 +11,17 @@
 
 #include <stdint.h>
 
-#include "mojo/edk/system/mutex.h"
 #include "mojo/edk/system/test/simple_test_thread.h"
 #include "mojo/edk/system/test/sleep.h"
 #include "mojo/edk/system/test/stopwatch.h"
 #include "mojo/edk/system/test/timeouts.h"
+#include "mojo/edk/util/mutex.h"
 #include "mojo/public/cpp/system/macros.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using mojo::util::Mutex;
+using mojo::util::MutexLocker;
+
 namespace mojo {
 namespace system {
 namespace {