Change POST-exclusion to idempotent-inclusion

components/data_reduction_proxy/core/common/data_reduction_proxy_util.cc

Index: components/data_reduction_proxy/core/common/data_reduction_proxy_util.cc
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_util.cc b/components/data_reduction_proxy/core/common/data_reduction_proxy_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..40d46f7ab849f10d831287cb1b2b3f2e7ae86918
--- /dev/null
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_util.cc
@@ -0,0 +1,14 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_util.h"
+
+namespace data_reduction_proxy {
+
+bool IsMethodIdempotent(const std::string& method) {
+  return method == "GET" || method == "OPTIONS" || method == "HEAD" ||
+         method == "PUT" || method == "DELETE" || method == "TRACE";
+}
+
+}  // namespace data_reduction_proxy