Move FileEnumerator to its own file, do some refactoring.

chrome/browser/extensions/api/serial/serial_port_enumerator_posix.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/serial/serial_port_enumerator.h"
 
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/string_util.h"
 #include "content/public/browser/browser_thread.h"
 
 using content::BrowserThread;
 
 namespace extensions {
 
 // static
 SerialPortEnumerator::StringSet SerialPortEnumerator::GenerateValidPatterns() {
@@ skipping 42 matching lines @@
 // removed from the system, so we really do want to regenerate the set each
 // time.
 //
 // TODO(miket): this might be refactorable into serial_connection.cc, if
 // Windows serial-port enumeration also entails looking through a directory.
 SerialPortEnumerator::StringSet
 SerialPortEnumerator::GenerateValidSerialPortNames() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   const base::FilePath kDevRoot("/dev");
   const int kFilesAndSymLinks =
-      file_util::FileEnumerator::FILES |
-      file_util::FileEnumerator::SHOW_SYM_LINKS;
+      base::FileEnumerator::FILES |
+      base::FileEnumerator::SHOW_SYM_LINKS;
 
   StringSet valid_patterns = GenerateValidPatterns();
   StringSet name_set;
-  file_util::FileEnumerator enumerator(
-      kDevRoot, false, kFilesAndSymLinks);
+  base::FileEnumerator enumerator(kDevRoot, false, kFilesAndSymLinks);
   do {
     const base::FilePath next_device_path(enumerator.Next());
     const std::string next_device = next_device_path.value();
     if (next_device.empty())
       break;
 
     StringSet::const_iterator i = valid_patterns.begin();
     for (; i != valid_patterns.end(); ++i) {
       if (MatchPattern(next_device, *i)) {
         name_set.insert(next_device);
         break;
       }
     }
   } while (true);
 
   return name_set;
 }
 
 }  // namespace extensions