Update documentation for vpnProvider

extensions/common/api/vpn_provider.idl

 // 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.
 
 // Use the <code>chrome.vpnProvider</code> API to implement a VPN
 // client.
 namespace vpnProvider {
   // A parameters class for the VPN interface.
   dictionary Parameters {
     // IP address for the VPN interface in CIDR notation.
     // IPv4 is currently the only supported mode.
     DOMString address;
     // Broadcast address for the VPN interface. (default: deduced
     // from IP address and mask)
     DOMString? broadcastAddress;
     // MTU setting for the VPN interface. (default: 1500 bytes)
     DOMString? mtu;
     // Exclude network traffic to the list of IP blocks in CIDR notation from
     // the tunnel. This can be used to bypass traffic to and from the VPN
     // server.
     // When many rules match a destination, the rule with the longest matching
     // prefix wins.
+    // Entries that correspond to the same CIDR block are treated as duplicates.
+    // Such duplicates in the collated (exclusionList + inclusionList) list are
+    // eliminated and the exact duplicate entry that will be eliminated is
+    // undefined.
     DOMString[] exclusionList;
     // Include network traffic to the list of IP blocks in CIDR notation to the
-    // tunnel. By default all user traffic is routed to the tunnel. This
-    // parameter can be used to setup split tunnel.
+    // tunnel. This parameter can be used to set up a split tunnel. By default
+    // no traffic is directed to the tunnel. Adding the entry "0.0.0.0/0" to
+    // this list gets all the user traffic redirected to the tunnel.
     // When many rules match a destination, the rule with the longest matching
     // prefix wins.
+    // Entries that correspond to the same CIDR block are treated as duplicates.
+    // Such duplicates in the collated (exclusionList + inclusionList) list are
+    // eliminated and the exact duplicate entry that will be eliminated is
+    // undefined.
     DOMString[] inclusionList;
     // A list of search domains. (default: no search domain)
     DOMString[]? domainSearch;
     // A list of IPs for the DNS servers.
     DOMString[] dnsServers;
   };
 
   // The enum is used by the platform to notify the client of the VPN session
   // status.
   enum PlatformMessage {
@@ skipping 71 matching lines @@
     // session owned by the extension.
     // |data|: The IP packet received from the platform.
     static void onPacketReceived(ArrayBuffer data);
 
     // Triggered when a configuration created by the extension is removed by the
     // platform.
     // |name|: Name of the configuration removed.
     static void onConfigRemoved(DOMString name);
   };
 };