Cast: Add JS API to get raw events logs from cast extension.

chrome/common/extensions/api/cast_streaming_rtp_stream.idl

Index: chrome/common/extensions/api/cast_streaming_rtp_stream.idl
diff --git a/chrome/common/extensions/api/cast_streaming_rtp_stream.idl b/chrome/common/extensions/api/cast_streaming_rtp_stream.idl
index 310db2f49fdd3e283c13d6f78e417242ba69f7c8..1c82bb657e6f652d6c866d7ea5df7213218062ce 100644
--- a/chrome/common/extensions/api/cast_streaming_rtp_stream.idl
+++ b/chrome/common/extensions/api/cast_streaming_rtp_stream.idl
@@ -60,6 +60,20 @@ namespace cast.streaming.rtpStream {
   // |id| : The ID for the RTP stream.
   callback CreateCallback = void (long streamId);
 
+  // Callback from the <code>getRawEvents</code> method.
+  // |rawEvents|: events encoded in protocol buffer format along with other 
+  // data serialized as a string.
+  // The serialization format can be found at 
+  // media/cast/logging/log_serializer.cc.
+  callback GetRawEventsCallback = void (DOMString rawEvents);
+  
+  // Callback from the <code>getStats</code> method.
+  // |rawEvents|: stats encoded in protocol buffer format along with other 
+  // data serialized as a string.
+  // The serialization format can be found at 
+  // media/cast/logging/log_serializer.cc.
+  callback GetStatsCallback = void (DOMString stats);
+
   interface Functions {
     // Destroys a Cast RTP stream.
     // |streamId| : The RTP stream ID.
@@ -79,6 +93,23 @@ namespace cast.streaming.rtpStream {
     // Stops activity on the specified stream.
     // |streamId| : The RTP stream ID.
     [nocompile] static void stop(long streamId);
+
+    // Starts logging for a stream.
+    [nocompile] static void startLogging(long streamId);

[Alpha Left Google, 2014/02/24 20:18:56]

This should be enableRawEventsLogging(long streamId, bool enabled);

Having just a startXXX() but no stopXXX() doesn't feel right. A simple
enableXXX() is probably the best.

[imcheng, 2014/02/24 21:28:26]

Per discussion, we can have a way to stop logging and free up memory. But I want
to name it toggleLogging or similar - passing false to a function named
"enableXXX" in order to disable something seems odd.

+    
+    // Get raw events for a stream in the current session.
+    // |startLogging()| must have been called before.
+    // |streamId|: Stream to get events for.
+    // |callback|: Called with the raw events Blob.
+    [nocompile] static void getRawEvents(
+        long streamId, GetRawEventsCallback callback);
+    
+    // Get stats for a stream in the current session.
+    // |startLogging()| must have been called before.
+    // |streamId|: Stream to get stats for.
+    // |callback|: Called with the stats Blob.
+    [nocompile] static void getStats(
+        long streamId, GetStatsCallback callback);
   };
 
   interface Events {