Move ReadFileToString to the base namespace.

chrome/test/base/web_ui_browsertest.cc

Index: chrome/test/base/web_ui_browsertest.cc
diff --git a/chrome/test/base/web_ui_browsertest.cc b/chrome/test/base/web_ui_browsertest.cc
index add13a73ba8b1951d6b40e9b1ed4cff377aed909..a32720cb7ba1c89989b3819756d312068ff45a5d 100644
--- a/chrome/test/base/web_ui_browsertest.cc
+++ b/chrome/test/base/web_ui_browsertest.cc
@@ -457,15 +457,15 @@ void WebUIBrowserTest::BuildJavascriptLibraries(string16* content) {
        ++user_libraries_iterator) {
     std::string library_content;
     if (user_libraries_iterator->IsAbsolute()) {
-      ASSERT_TRUE(file_util::ReadFileToString(*user_libraries_iterator,
+      ASSERT_TRUE(base::ReadFileToString(*user_libraries_iterator,
                                               &library_content))
           << user_libraries_iterator->value();
     } else {
-      bool ok = file_util::ReadFileToString(
+      bool ok = base::ReadFileToString(
           gen_test_data_directory_.Append(*user_libraries_iterator),
           &library_content);
       if (!ok) {
-        ok = file_util::ReadFileToString(
+        ok = base::ReadFileToString(
             test_data_directory_.Append(*user_libraries_iterator),
             &library_content);
       }