clean-up libutils includes

moved Foo.h as first include of Foo.cpp, and
removed redundant includes.

Made NativeHandle non virtual.


Test: run & compile
Bug: n/a

Change-Id: I37fa746cd42c9ba23aba181f84cb6c619386406a
diff --git a/libutils/StopWatch.cpp b/libutils/StopWatch.cpp
index 8c7b596..219c13c 100644
--- a/libutils/StopWatch.cpp
+++ b/libutils/StopWatch.cpp
@@ -16,9 +16,7 @@
 
 #define LOG_TAG "StopWatch"
 
-#include <string.h>
-#include <stdlib.h>
-#include <stdio.h>
+#include <utils/StopWatch.h>
 
 /* for PRId64 */
 #ifndef __STDC_FORMAT_MACROS
@@ -27,8 +25,6 @@
 #include <inttypes.h>
 
 #include <utils/Log.h>
-#include <utils/Errors.h>
-#include <utils/StopWatch.h>
 
 /*****************************************************************************/