[update_engine] Update to use not-hideously-old logging API from chrome

BUG=None
TEST=compile

Change-Id: Ieed8952b6806a72b59e16c1579f7293b6a98157a

Review URL: http://codereview.chromium.org/3170010
diff --git a/file_writer.h b/file_writer.h
index ebb8535..1a0cc23 100644
--- a/file_writer.h
+++ b/file_writer.h
@@ -9,7 +9,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include "chromeos/obsolete_logging.h"
+#include "base/logging.h"
 #include "update_engine/utils.h"
 
 // FileWriter is a class that is used to (synchronously, for now) write to