Keep only base/extractor.[cc|h].

precompile/precompile.cc

Index: precompile/precompile.cc
diff --git a/precompile/precompile.cc b/precompile/precompile.cc
deleted file mode 100644
index a108af7629669c7d3c0483bddcdbba07ebee8e8b..0000000000000000000000000000000000000000
--- a/precompile/precompile.cc
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2004-2009 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// ========================================================================
-
-// 4505: unreferenced local function has been removed
-#pragma warning(disable : 4505)
-