Move WriteFile and WriteFileDescriptor from file_util to base namespace.

extensions/browser/value_store/leveldb_value_store_unittest.cc

Index: extensions/browser/value_store/leveldb_value_store_unittest.cc
diff --git a/extensions/browser/value_store/leveldb_value_store_unittest.cc b/extensions/browser/value_store/leveldb_value_store_unittest.cc
index 8582e1e16943829ec85b0388474129444234a7ec..c278b54918ddbd7f3e98362f84571c0e2dd79c71 100644
--- a/extensions/browser/value_store/leveldb_value_store_unittest.cc
+++ b/extensions/browser/value_store/leveldb_value_store_unittest.cc
@@ -166,7 +166,7 @@ TEST_F(LeveldbValueStoreUnitTest, RestoreFullDatabase) {
   for (base::FilePath file = enumerator.Next(); !file.empty();
        file = enumerator.Next()) {
     // WriteFile() failure is a result of -1.
-    ASSERT_NE(file_util::WriteFile(file, kLolCats.c_str(), kLolCats.length()),
+    ASSERT_NE(base::WriteFile(file, kLolCats.c_str(), kLolCats.length()),
               -1);
   }
   OpenStore();