[chrome.dial] Adds chrome.dial.fetchDeviceDecription API.

chrome/common/extensions/api/dial.idl

 // 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.
 
 // Use the <code>chrome.dial</code> API to discover devices that support DIAL.
 // Protocol specification: http://www.dial-multiscreen.org/
 namespace dial {
 
   // Represents a unique device that responded to a DIAL discovery request.
   dictionary DialDevice {
 
     // A label identifying the device within this instance of the browser.
     // Not guaranteed to persist beyond browser instances.
     DOMString deviceLabel;
 
     // A URL pointing to the device description resource for the device.
     DOMString deviceDescriptionUrl;
 
     // The uPnP configuration ID reported by the device.  Corresponds to the
     // CONFIGID.UPNP.ORG header in the M-SEARCH response.
     long? configId;
   };
 
+  // Represents a device description resource successfully fetched from a
+  // DIAL device.
+  dictionary DialDeviceDescription {
+
+    // The label of the device that the description was fetched for.
+    DOMString deviceLabel;
+
+    // The contents of the Application-URL header in the response.
+    DOMString appUrl;
+
+    // The content of the response body.  This will be an XML document
+    // (hopefully) conforming to section 2.3 of the UPnP spec.
+    DOMString deviceDescription;
+  };
+
   enum DialErrorCode {
     no_listeners,
     no_valid_network_interfaces,
     network_disconnected,
     cellular_network,
     socket_error,
     unknown
   };
 
   dictionary DialError {
     DialErrorCode code;
   };
 
   callback BooleanCallback = void (boolean result);
+  callback DeviceDescriptionCallback = void (DialDeviceDescription result);
 
   interface Functions {
 
     // Requests that DIAL discovery happen immediately.  The request may not be
     // honored as discovery may already be happening in the background.  The
     // callback is invoked with |true| if discovery was initiated or |false|
     // otherwise.
     static void discoverNow(BooleanCallback callback);
+
+    // Fetches the device description for the DIAL device identified by
+    // |deviceLabel|.  If successful, the callback is invoked with a
+    // DialDeviceDescription containing the content of the device description.
+    //
+    // If unsuccessful, callback is invoked with |null| and lastError is set
+    // to an error message.  If the error occurred during the HTTP fetch itself,
+    // the message will begin "HTTP XXX:" where XXX is the HTTP result code.

[imcheng, 2016/12/28 05:36:45]

... begin with

[mark a. foltz, 2017/01/04 00:20:16]

Done.

+    static void fetchDeviceDescription(DOMString deviceLabel,
+                                       DeviceDescriptionCallback callback);
   };
 
   interface Events {
 
     // Event fired to inform clients of the current, complete set of responsive
     // devices.  Clients should only need to store the list from the most recent
     // event.  May be fired in response to multiple circumstances:
     //
     // (1) The DIAL service refreshed its device list through periodic polling.
     // (2) A client invoked discoverNow().
     // (3) An event happened that should invalidate the device list
     //     (e.g., a network interface went offline), in which case it is fired
     //     with an empty array.
     static void onDeviceList(DialDevice[] result);
 
     // Event fired to inform clients on errors during device discovery.
     static void onError(DialError error);
   };
 };