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

extensions/common/api/cast_channel.idl

Index: extensions/common/api/cast_channel.idl
diff --git a/extensions/common/api/cast_channel.idl b/extensions/common/api/cast_channel.idl
index 9eb0b3e09d00641f4acf9ea7d0532e9ef7d9977c..3d2f7d827dda5d773fbff57a70df97b9c87e1473 100644
--- a/extensions/common/api/cast_channel.idl
+++ b/extensions/common/api/cast_channel.idl
@@ -151,6 +151,13 @@ namespace cast.channel {
   // 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
@@ -181,6 +188,12 @@ namespace cast.channel {
     // 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,
+    // an error will be raised.                
+    static void getLogs(GetLogsCallback callback);
   };
 
   // Events on the channel.