Move the rest of test_file_util to base namespace.

chrome/browser/download/download_browsertest.cc

Index: chrome/browser/download/download_browsertest.cc
diff --git a/chrome/browser/download/download_browsertest.cc b/chrome/browser/download/download_browsertest.cc
index 91525d254e70e40afe3b1765119d547c5b295a79..1e19c1ace8c1894395e00d85c99e2c5a1d4223c6 100644
--- a/chrome/browser/download/download_browsertest.cc
+++ b/chrome/browser/download/download_browsertest.cc
@@ -1041,8 +1041,8 @@ class DownloadTest : public InProcessBrowserTest {
     base::FilePath destination_folder = GetDownloadDirectory(browser());
     DVLOG(1) << " " << __FUNCTION__ << "()"
              << " folder = '" << destination_folder.value() << "'";
-    file_util::PermissionRestorer permission_restorer(destination_folder);
-    EXPECT_TRUE(file_util::MakeFileUnwritable(destination_folder));
+    base::FilePermissionRestorer permission_restorer(destination_folder);
+    EXPECT_TRUE(base::MakeFileUnwritable(destination_folder));
 
     for (size_t i = 0; i < count; ++i) {
       DownloadFilesCheckErrorsLoopBody(download_info[i], i);