Move FileEnumerator to its own file, do some refactoring.

cloud_print/virtual_driver/win/port_monitor/port_monitor.cc

Index: cloud_print/virtual_driver/win/port_monitor/port_monitor.cc
diff --git a/cloud_print/virtual_driver/win/port_monitor/port_monitor.cc b/cloud_print/virtual_driver/win/port_monitor/port_monitor.cc
index c13228adff54c9997ebbf11ed3d7940a95e77a85..900828577a4e26887920af78cc2960ee509d0ed2 100644
--- a/cloud_print/virtual_driver/win/port_monitor/port_monitor.cc
+++ b/cloud_print/virtual_driver/win/port_monitor/port_monitor.cc
@@ -15,6 +15,7 @@
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/process.h"
@@ -119,14 +120,11 @@ base::FilePath GetAppDataDir() {
 
 // Delete files which where not deleted by chrome.
 void DeleteLeakedFiles(const base::FilePath& dir) {
-  using file_util::FileEnumerator;
   base::Time delete_before = base::Time::Now() - base::TimeDelta::FromDays(1);
-  FileEnumerator enumerator(dir, false, FileEnumerator::FILES);
+  base::FileEnumerator enumerator(dir, false, base::FileEnumerator::FILES);
   for (base::FilePath file_path = enumerator.Next(); !file_path.empty();
        file_path = enumerator.Next()) {
-    FileEnumerator::FindInfo info;
-    enumerator.GetFindInfo(&info);
-    if (FileEnumerator::GetLastModifiedTime(info) < delete_before)
+    if (enumerator.GetInfo().GetLastModifiedTime() < delete_before)
       file_util::Delete(file_path, false);
   }
 }