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/Looper.cpp b/libutils/Looper.cpp
index 84bc028..6c57b2e 100644
--- a/libutils/Looper.cpp
+++ b/libutils/Looper.cpp
@@ -13,17 +13,8 @@
 // Debugs callback registration and invocation.
 #define DEBUG_CALLBACKS 0
 
-#include <errno.h>
-#include <fcntl.h>
-#include <inttypes.h>
-#include <limits.h>
-#include <string.h>
-#include <sys/eventfd.h>
-#include <unistd.h>
-
-#include <log/log.h>
 #include <utils/Looper.h>
-#include <utils/Timers.h>
+#include <sys/eventfd.h>
 
 namespace android {