Add GetBoundAddress to PPB_UDPSocket_Private

ppapi/api/private/ppb_udp_socket_private.idl

Index: ppapi/api/private/ppb_udp_socket_private.idl
diff --git a/ppapi/api/private/ppb_udp_socket_private.idl b/ppapi/api/private/ppb_udp_socket_private.idl
index 4babbb4a4dbd915a962d354947fd3f986b5d4823..ecc346d20723099074b42e02ca8243ccdf093125 100644
--- a/ppapi/api/private/ppb_udp_socket_private.idl
+++ b/ppapi/api/private/ppb_udp_socket_private.idl
@@ -27,6 +27,12 @@ interface PPB_UDPSocket_Private {
                [in] PP_NetAddress_Private addr,
                [in] PP_CompletionCallback callback);
 
+  /* Upon successful completion of Bind, the address that we have
+   * bound to is stored in |addr|

[yzshen1, 2012/02/06 06:51:27]

Nit: This comment is inaccurate. The address is not stored in |addr| upon
successful completion of Bind. It should be something like: "Returns the address
that the socket has bound to. It won't succeed unless Bind has completed
successfully."

[mtilburg1, 2012/02/06 15:11:35]

Done.

+   */
+  PP_Bool GetBoundAddress([in] PP_Resource udp_socket,

[yzshen1, 2012/02/06 06:51:27]

You need to consider backward compatibility. This method should be in a newer
interface, say, 0.3. It has all methods from the older version, plus the new
one.

And you need to return 0.2 or 0.3 interface according to what the plugin asks
for.

http://codereview.chromium.org/9307115/ is an example of adding new methods
while maintaining backward compatibility.

[mtilburg1, 2012/02/06 15:11:35]

I added M18 = 0.3.... is this correct?  When I added M17 = 0.3, generating the
header file did not have the same effect(only version 0.3 was generated, no
0.2), but I'm not M18 is correct either???
On 2012/02/06 06:51:27, yzshen1 wrote:

[yzshen1, 2012/02/06 18:12:50]

Please use M19.

+                          [out] PP_NetAddress_Private addr);
+
   /* Performs a non-blocking recvfrom call on socket.
    * Bind must be called first. |callback| is invoked when recvfrom
    * reads data.  You must call GetRecvFromAddress to recover the