Revert of Move BenchTimer to tools as Timer

tools/timer/SysTimer_posix.h

Index: tools/timer/SysTimer_posix.h
diff --git a/tools/timer/SysTimer_posix.h b/tools/timer/SysTimer_posix.h
deleted file mode 100644
index 1eca909e269e168377054747467922ea6e5275d9..0000000000000000000000000000000000000000
--- a/tools/timer/SysTimer_posix.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- * Copyright 2011 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#ifndef SysTimer_DEFINED
-#define SysTimer_DEFINED
-
-#include <time.h>
-
-class SysTimer {
-public:
-    void startWall();
-    void startCpu();
-    double endCpu();
-    double endWall();
-private:
-    timespec fCpu;
-    timespec fWall;
-};
-
-#endif