[chrome.displaySource] Switch mojom targets to use STL types.

extensions/common/mojo/wifi_display_session_service.mojom

 // 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.
 
 module extensions;
 
+struct WiFiDisplayMediaPacket {
+  array<uint8> data;
+};
+
 // WiFiDisplaySessionService class provides access to the network for
 // the render-hosted Wi-Fi Display session.
 interface WiFiDisplaySessionService {
   SetClient(WiFiDisplaySessionServiceClient client);
 
   // Requires connection to a sink using the given authentication information.
   // Note: 'auth_method' values must correspond to 'enum AuthenticationMethod'
   // from display_source.idl
   Connect(int32 sink_id, int32 auth_method, string auth_data);
 
@@ skipping 27 matching lines @@
   OnMessage(string data);
 };
 
 // This interface is used to send media stream to the
 // connected sink.
 interface WiFiDisplayMediaService {
   // Sets the destination point for sending media stream.
   SetDesinationPoint(string ip_address, int32 port) => (bool success);
 
   // Sends media packet to the destination point.
-  SendMediaPacket(array<uint8> packet);
+  SendMediaPacket(WiFiDisplayMediaPacket packet);
 };