Make BootstrapSandboxPolicy a struct, containing the existing rule map and a new default rule.

sandbox/mac/policy.h

 // Copyright 2014 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 SANDBOX_MAC_POLICY_H_
 #define SANDBOX_MAC_POLICY_H_
 
 #include <mach/mach.h>
 
 #include <map>
@@ skipping 29 matching lines @@
   explicit Rule(mach_port_t override_port);
 
   PolicyDecision result;
 
   // The Rule does not take ownership of this port, but additional send rights
   // will be allocated to it before it is sent to a client. This name must
   // denote a send right that can duplicated with MACH_MSG_TYPE_COPY_SEND.
   mach_port_t substitute_port;
 };
 
-// A SandboxPolicy maps bootstrap server names to policy Rules.
-typedef std::map<std::string, Rule> BootstrapSandboxPolicy;
+// A policy object manages the rules enforced on a target sandboxed process.
+struct SANDBOX_EXPORT BootstrapSandboxPolicy {
+  typedef std::map<std::string, Rule> NamedRules;
+
+  BootstrapSandboxPolicy();
+  ~BootstrapSandboxPolicy();
+
+  // The default action to take if the server name being looked up is not
+  // present in |rules|.
+  Rule default_rule;
+
+  // A map of bootstrap server names to policy Rules.
+  NamedRules rules;
+};
 
 // Checks that a policy is well-formed.
 SANDBOX_EXPORT bool IsPolicyValid(const BootstrapSandboxPolicy& policy);
 
 }  // namespace sandbox
 
 #endif  // SANDBOX_MAC_POLICY_H_