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

content/browser/download/download_item_impl.cc

Index: content/browser/download/download_item_impl.cc
diff --git a/content/browser/download/download_item_impl.cc b/content/browser/download/download_item_impl.cc
index 67a629d5b9b4d64b25c83006bed921470df73865..07c7558d762d509b3d1d741bf4c130bcc53af234 100644
--- a/content/browser/download/download_item_impl.cc
+++ b/content/browser/download/download_item_impl.cc
@@ -61,7 +61,7 @@ void DeleteDownloadedFile(const base::FilePath& path) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
   // Make sure we only delete files.
-  if (!file_util::DirectoryExists(path))
+  if (!base::DirectoryExists(path))
     base::Delete(path, false);
 }