Move FileEnumerator to its own file, do some refactoring.

chrome/browser/history/text_database_manager.cc

Index: chrome/browser/history/text_database_manager.cc
diff --git a/chrome/browser/history/text_database_manager.cc b/chrome/browser/history/text_database_manager.cc
index f6ca82e245bbe863499fa6cb7a597cf969a7e519..fee0d6f61ac4039cab5d3cda64eb8c84801ee9c6 100644
--- a/chrome/browser/history/text_database_manager.cc
+++ b/chrome/browser/history/text_database_manager.cc
@@ -10,6 +10,7 @@
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/metrics/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
@@ -160,8 +161,8 @@ void TextDatabaseManager::InitDBList() {
   // Find files on disk matching our pattern so we can quickly test for them.
   base::FilePath::StringType filepattern(TextDatabase::file_base());
   filepattern.append(FILE_PATH_LITERAL("*"));
-  file_util::FileEnumerator enumerator(
-      dir_, false, file_util::FileEnumerator::FILES, filepattern);
+  base::FileEnumerator enumerator(
+      dir_, false, base::FileEnumerator::FILES, filepattern);
   base::FilePath cur_file;
   while (!(cur_file = enumerator.Next()).empty()) {
     // Convert to the number representing this file.