[DO NOT COMMIT] Re-use the dafsa code for s-w-r histograms

net/base/dafsa/lookup_string.h

Index: net/base/dafsa/lookup_string.h
diff --git a/net/base/dafsa/lookup_string.h b/net/base/dafsa/lookup_string.h
new file mode 100644
index 0000000000000000000000000000000000000000..0d87f5f4050fe1c0e33d0e3735d4fbd88cbcc3dc
--- /dev/null
+++ b/net/base/dafsa/lookup_string.h
@@ -0,0 +1,29 @@
+// Copyright 2015 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.
+
+#ifndef NET_BASE_DAFSA_LOOKUP_STRING_H_
+#define NET_BASE_DAFSA_LOOKUP_STRING_H_
+
+#include <stddef.h>
+
+#include "net/base/net_export.h"
+
+namespace net {
+
+const int kDafsaNotFound = -1;
+const int kDafsaExceptionRule = 1;
+const int kDafsaWildcardRule = 2;
+const int kDafsaPrivateRule = 4;
+
+// Lookup a domain key in a byte array |graph| generated by make_dafsa.py.  The
+// rule type is returned if |key| is found, otherwise kDafsaNotFound is
+// returned.
+int NET_EXPORT_PRIVATE LookupStringInDafsa(const unsigned char* graph,
+                                           size_t length,
+                                           const char* key,
+                                           size_t key_length);
+
+}  // namespace net
+
+#endif  // NET_BASE_DAFSA_LOOKUP_STRING_H_