Add more string_util functions to base namespace.

chrome/browser/prefs/profile_pref_store_manager_unittest.cc

Index: chrome/browser/prefs/profile_pref_store_manager_unittest.cc
diff --git a/chrome/browser/prefs/profile_pref_store_manager_unittest.cc b/chrome/browser/prefs/profile_pref_store_manager_unittest.cc
index 6d4f2e1dfb63f49d17c79038610e72aed0a2b73e..49b94d4e51ded329d8012b8603824d23a0d377dd 100644
--- a/chrome/browser/prefs/profile_pref_store_manager_unittest.cc
+++ b/chrome/browser/prefs/profile_pref_store_manager_unittest.cc
@@ -238,7 +238,7 @@ class ProfilePrefStoreManagerTest : public testing::Test {
       // Tamper with the file's contents
       std::string contents;
       EXPECT_TRUE(base::ReadFileToString(path, &contents));
-      ReplaceSubstringsAfterOffset(&contents, 0u, find, replace);
+      base::ReplaceSubstringsAfterOffset(&contents, 0u, find, replace);
       EXPECT_EQ(static_cast<int>(contents.length()),
                 base::WriteFile(path, contents.c_str(), contents.length()));
     }