Move ReadFileToString to the base namespace.

chrome/browser/extensions/api/push_messaging/sync_setup_helper.cc

Index: chrome/browser/extensions/api/push_messaging/sync_setup_helper.cc
diff --git a/chrome/browser/extensions/api/push_messaging/sync_setup_helper.cc b/chrome/browser/extensions/api/push_messaging/sync_setup_helper.cc
index f4dffc3e9160c6592938b55fa89e73b636f5d378..51fc4b3f7f98d4f325910012d24fcf8f9249fcba 100644
--- a/chrome/browser/extensions/api/push_messaging/sync_setup_helper.cc
+++ b/chrome/browser/extensions/api/push_messaging/sync_setup_helper.cc
@@ -50,7 +50,7 @@ bool SyncSetupHelper::InitializeSync(Profile* profile) {
 bool SyncSetupHelper::ReadPasswordFile(const base::FilePath& password_file) {
   // TODO(dcheng): Convert format of config file to JSON.
   std::string file_contents;
-  bool success = file_util::ReadFileToString(password_file, &file_contents);
+  bool success = base::ReadFileToString(password_file, &file_contents);
   EXPECT_TRUE(success)
       << "Password file \""
       << password_file.value() << "\" does not exist.";