Move prefix_set and parts of safe_browsing_util into a new component safe_browsing_db.

components/safe_browsing_db/safe_browsing_db_util.h

Index: components/safe_browsing_db/safe_browsing_db_util.h
diff --git a/components/safe_browsing_db/safe_browsing_db_util.h b/components/safe_browsing_db/safe_browsing_db_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..cf5a4a46bb92c2f62a2893bbceddfb807764badd
--- /dev/null
+++ b/components/safe_browsing_db/safe_browsing_db_util.h
@@ -0,0 +1,62 @@
+// Copyright (c) 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.
+//
+// Utilities for the SafeBrowsing DB code.
+
+#ifndef COMPONENTS_SAFE_BROWSING_DB_SAFE_BROWSING_DB_UTIL_H_
+#define COMPONENTS_SAFE_BROWSING_DB_SAFE_BROWSING_DB_UTIL_H_
+
+#include "base/basictypes.h"
+#include "base/strings/string_piece.h"
+
+// A truncated hash's type.
+typedef uint32 SBPrefix;
+
+// A full hash.
+union SBFullHash {
+  char full_hash[32];
+  SBPrefix prefix;
+};
+
+inline bool SBFullHashEqual(const SBFullHash& a, const SBFullHash& b) {
+  return !memcmp(a.full_hash, b.full_hash, sizeof(a.full_hash));
+}
+
+inline bool SBFullHashLess(const SBFullHash& a, const SBFullHash& b) {
+  return memcmp(a.full_hash, b.full_hash, sizeof(a.full_hash)) < 0;
+}
+
+// Generate full hash for the given string.
+SBFullHash SBFullHashForString(const base::StringPiece& str);
+
+// Different types of threats that SafeBrowsing protects against.
+enum SBThreatType {
+  // No threat at all.
+  SB_THREAT_TYPE_SAFE,
+
+  // The URL is being used for phishing.
+  SB_THREAT_TYPE_URL_PHISHING,
+
+  // The URL hosts malware.
+  SB_THREAT_TYPE_URL_MALWARE,
+
+  // The URL hosts unwanted programs.
+  SB_THREAT_TYPE_URL_UNWANTED,
+
+  // The download URL is malware.
+  SB_THREAT_TYPE_BINARY_MALWARE_URL,
+
+  // Url detected by the client-side phishing model.  Note that unlike the
+  // above values, this does not correspond to a downloaded list.
+  SB_THREAT_TYPE_CLIENT_SIDE_PHISHING_URL,
+
+  // The Chrome extension or app (given by its ID) is malware.
+  SB_THREAT_TYPE_EXTENSION,
+
+  // Url detected by the client-side malware IP list. This IP list is part
+  // of the client side detection model.
+  SB_THREAT_TYPE_CLIENT_SIDE_MALWARE_URL,
+};
+
+#endif  // COMPONENTS_SAFE_BROWSING_DB_SAFE_BROWSING_DB_UTIL_H_