Move WriteFile and WriteFileDescriptor from file_util to base namespace.

chrome/browser/chromeos/login/resource_loader_browsertest.cc

Index: chrome/browser/chromeos/login/resource_loader_browsertest.cc
diff --git a/chrome/browser/chromeos/login/resource_loader_browsertest.cc b/chrome/browser/chromeos/login/resource_loader_browsertest.cc
index 2b91a325dacd5bb3461383ef19902c52a0011282..668a373451d426ed20b2d3e017e7cc87b2fe404b 100644
--- a/chrome/browser/chromeos/login/resource_loader_browsertest.cc
+++ b/chrome/browser/chromeos/login/resource_loader_browsertest.cc
@@ -23,7 +23,7 @@ namespace {
 GURL CreateResource(const std::string& content) {
   base::FilePath path;
   EXPECT_TRUE(base::CreateTemporaryFile(&path));
-  EXPECT_TRUE(file_util::WriteFile(path, content.c_str(), content.size()));
+  EXPECT_TRUE(base::WriteFile(path, content.c_str(), content.size()));
   return GURL("file:///" + path.AsUTF8Unsafe());
 }