Move MatchPattern to its own header and the base namespace.

base/strings/pattern.h

+// 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 BASE_STRINGS_PATTERN_H_
+#define BASE_STRINGS_PATTERN_H_
+
+#include "base/base_export.h"
+#include "base/strings/string_piece.h"
+
+namespace base {
+
+// Returns true if the string passed in matches the pattern. The pattern
+// string can contain wildcards like * and ?
+//
+// The backslash character (\) is an escape character for * and ?
+// We limit the patterns to having a max of 16 * or ? characters.
+// ? matches 0 or 1 character, while * matches 0 or more characters.
+BASE_EXPORT bool MatchPattern(const StringPiece& string,
+                              const StringPiece& pattern);
+BASE_EXPORT bool MatchPattern(const StringPiece16& string,
+                              const StringPiece16& pattern);
+
+}  // namespace base
+
+#endif  // BASE_STRINGS_PATTERN_H_