Cast channel: Add cast.channel.getLogs extension API.

extensions/common/api/cast_channel.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.
 
 // API for communicating with a Google Cast device over an authenticated
 // channel.
 namespace cast.channel {
 
   // The state of the channel.
   enum ReadyState {
@@ skipping 109 matching lines @@
     DOMString sourceId;
     DOMString destinationId;
 
     // The content of the message.  Must be either a string or an ArrayBuffer.
     any data;
   };
 
   // Callback holding the result of a channel operation.
   callback ChannelInfoCallback = void (ChannelInfo result);
 
+  // Callback from <code>getLogs</code> method.
+  // |log|: compressed serialized raw bytes containing the logs.
+  // The log is formatted using protocol buffer.
+  // See extensions/browser/api/cast_channel/logging.proto for definition.
+  // Compression is in gzip format.
+  callback GetLogsCallback = void (ArrayBuffer log);
+  
   interface Functions {
     // Opens a new channel to the Cast receiver specified by connectInfo.  Only
     // one channel may be connected to same receiver from the same extension at
     // a time.  If the open request is successful, the callback will be invoked
     // with a ChannelInfo with readyState == 'connecting'.  If unsuccessful, the
     // callback will be invoked with a ChannelInfo with channel.readyState ==
     // 'closed' and channel.errorState will be set to the error condition.
     //
     // TODO(mfoltz): Convert 'any' to ConnectInfo once all clients are updated
     // to not send URLs.
     static void open(any connectInfo,
                      ChannelInfoCallback callback);
 
     // Sends a message on the channel and invokes callback with the resulting
     // channel status.  The channel must be in readyState == 'open'.  If
     // unsuccessful, channel.readyState will be set to 'closed',
     // channel.errorState will be set to the error condition.
     static void send(ChannelInfo channel,
                      MessageInfo message,
                      ChannelInfoCallback callback);
 
     // Requests that the channel be closed and invokes callback with the
     // resulting channel status.  The channel must be in readyState == 'open' or
     // 'connecting'.  If successful, onClose will be fired with readyState ==
     // 'closed'.  If unsuccessful, channel.readyState will be set to 'closed',
     // and channel.errorState will be set to the error condition.
     static void close(ChannelInfo channel,
                       ChannelInfoCallback callback);
+      
+    // Get logs in compressed serialized format. See GetLogsCallback for
+    // details.  
+    // |callback|: If successful, |callback| is invoked with data. Otherwise,
+    // it is invoked with an empty ArrayBuffer.                

[mark a. foltz, 2014/08/11 23:01:44]

I think the preferred approach is to use chrome.runtime.lastError to report
errors instead.  See the examples in other API functions.

[imcheng, 2014/08/12 07:42:10]

Done. I assume this is done using SetError()? Is the new comment accurate?

+    static void getLogs(GetLogsCallback callback);
   };
 
   // Events on the channel.
   interface Events {
     // Fired when a message is received on an open channel.
     static void onMessage(ChannelInfo channel,
                           MessageInfo message);
 
     // Fired when an error occurs as a result of a channel method or a network
     // event.
     static void onError(ChannelInfo channel);
   };
 };