Fix linter issues on HardwareInterface.

BUG=None
TEST=Passed cpplinter and unit tests.

Change-Id: I0eafef46a1cde54c62f4fa4ffbe13df5cf73e795
Reviewed-on: https://chromium-review.googlesource.com/197586
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
Tested-by: Alex Deymo <deymo@chromium.org>
diff --git a/hardware.h b/hardware.h
index 99c0803..8183c51 100644
--- a/hardware.h
+++ b/hardware.h
@@ -5,9 +5,12 @@
 #ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_H_
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_H_
 
-#include "update_engine/hardware_interface.h"
+#include <string>
+#include <vector>
 
-#include "base/basictypes.h"
+#include <base/basictypes.h>
+
+#include "update_engine/hardware_interface.h"
 
 namespace chromeos_update_engine {