Move FileEnumerator to its own file, do some refactoring.

chrome/browser/printing/printing_layout_browsertest.cc

Index: chrome/browser/printing/printing_layout_browsertest.cc
diff --git a/chrome/browser/printing/printing_layout_browsertest.cc b/chrome/browser/printing/printing_layout_browsertest.cc
index d97762b38e39d1b7d5898bde6e2589c9968e7daa..33b296a7efd22ff2a79dd810090ec84b77682800 100644
--- a/chrome/browser/printing/printing_layout_browsertest.cc
+++ b/chrome/browser/printing/printing_layout_browsertest.cc
@@ -4,6 +4,7 @@
 
 #include "base/command_line.h"
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
@@ -197,8 +198,8 @@ class PrintingLayoutTest : public PrintingTest<InProcessBrowserTest>,
     bool found_emf = false;
     bool found_prn = false;
     for (int i = 0; i < 100; ++i) {
-      file_util::FileEnumerator enumerator(emf_path_, false,
-          file_util::FileEnumerator::FILES);
+      base::FileEnumerator enumerator(emf_path_, false,
+                                      base::FileEnumerator::FILES);
       emf_file.clear();
       prn_file.clear();
       found_emf = false;