Move PathIsWritable, DirectoryExists, ContentsEqual, and TextContentsEqual to the base namespace.

net/base/directory_lister.cc

Index: net/base/directory_lister.cc
diff --git a/net/base/directory_lister.cc b/net/base/directory_lister.cc
index 2f7e473d17b9c344864bd3378d56fbea2e6546ee..e15590604bf84bc250a9d36f57d2d03986b34fcd 100644
--- a/net/base/directory_lister.cc
+++ b/net/base/directory_lister.cc
@@ -143,7 +143,7 @@ void DirectoryLister::Core::Cancel() {
 
 void DirectoryLister::Core::StartInternal() {
 
-  if (!file_util::DirectoryExists(dir_)) {
+  if (!base::DirectoryExists(dir_)) {
     origin_loop_->PostTask(
         FROM_HERE,
         base::Bind(&DirectoryLister::Core::OnDone, this, ERR_FILE_NOT_FOUND));