Move FileEnumerator to its own file, do some refactoring.

chrome/test/webdriver/webdriver_util.cc

Index: chrome/test/webdriver/webdriver_util.cc
diff --git a/chrome/test/webdriver/webdriver_util.cc b/chrome/test/webdriver/webdriver_util.cc
index 274144c3528a0cf64be1901ef07924630e63bb87..54833a80010502d97feed859713d3328b8192f97 100644
--- a/chrome/test/webdriver/webdriver_util.cc
+++ b/chrome/test/webdriver/webdriver_util.cc
@@ -7,6 +7,7 @@
 #include "base/base64.h"
 #include "base/basictypes.h"
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/format_macros.h"
 #include "base/json/json_reader.h"
@@ -372,9 +373,8 @@ bool UnzipSoleFile(const base::FilePath& unzip_dir,
     return false;
   }
 
-  file_util::FileEnumerator enumerator(unzip_dir, false /* recursive */,
-      file_util::FileEnumerator::FILES |
-      file_util::FileEnumerator::DIRECTORIES);
+  base::FileEnumerator enumerator(unzip_dir, false /* recursive */,
+      base::FileEnumerator::FILES | base::FileEnumerator::DIRECTORIES);
   base::FilePath first_file = enumerator.Next();
   if (first_file.empty()) {
     *error_msg = "Zip contained 0 files";