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/BlobCache.cpp b/libutils/BlobCache.cpp
index 126995b..b0fdd44 100644
--- a/libutils/BlobCache.cpp
+++ b/libutils/BlobCache.cpp
@@ -17,13 +17,10 @@
 #define LOG_TAG "BlobCache"
 //#define LOG_NDEBUG 0
 
-#include <inttypes.h>
-#include <stdlib.h>
-#include <string.h>
-
 #include <utils/BlobCache.h>
-#include <utils/Errors.h>
-#include <utils/Log.h>
+#include <utils/Timers.h>
+
+#include <inttypes.h>
 
 #include <cutils/properties.h>