diff --git a/base/guid.cc b/base/guid.cc
new file mode 100644
index 0000000..be5c58b
--- /dev/null
+++ b/base/guid.cc
@@ -0,0 +1,30 @@
+// Copyright (c) 2012 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 "base/guid.h"
+
+#include "base/strings/string_util.h"
+
+namespace base {
+
+bool IsValidGUID(const std::string& guid) {
+  const size_t kGUIDLength = 36U;
+  if (guid.length() != kGUIDLength)
+    return false;
+
+  for (size_t i = 0; i < guid.length(); ++i) {
+    char current = guid[i];
+    if (i == 8 || i == 13 || i == 18 || i == 23) {
+      if (current != '-')
+        return false;
+    } else {
+      if (!IsHexDigit(current))
+        return false;
+    }
+  }
+
+  return true;
+}
+
+}  // namespace base