Move WriteFile and WriteFileDescriptor from file_util to base namespace.

chrome/browser/extensions/app_background_page_apitest.cc

Index: chrome/browser/extensions/app_background_page_apitest.cc
diff --git a/chrome/browser/extensions/app_background_page_apitest.cc b/chrome/browser/extensions/app_background_page_apitest.cc
index db030f019d8520e427a6dbb142eef66c6b35ec65..c423a8c7cd097f62ef884de80031973aa4c7c135 100644
--- a/chrome/browser/extensions/app_background_page_apitest.cc
+++ b/chrome/browser/extensions/app_background_page_apitest.cc
@@ -51,9 +51,9 @@ class AppBackgroundPageApiTest : public ExtensionApiTest {
       return false;
     }
     base::FilePath manifest_path = app_dir_.path().AppendASCII("manifest.json");
-    int bytes_written = file_util::WriteFile(manifest_path,
-                                             app_manifest.data(),
-                                             app_manifest.size());
+    int bytes_written = base::WriteFile(manifest_path,
+                                        app_manifest.data(),
+                                        app_manifest.size());
     if (bytes_written != static_cast<int>(app_manifest.size())) {
       LOG(ERROR) << "Unable to write complete manifest to file. Return code="
                  << bytes_written;