Allow audio debug recordings through a private API extension.

chrome/common/extensions/api/webrtc_logging_private.idl

 // Copyright 2013 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.webrtcLoggingPrivate</code> API to control diagnostic
 // WebRTC logging.
 namespace webrtcLoggingPrivate {
   dictionary MetaDataEntry {
     // The meta data entry key.
     DOMString key;
 
     // The meta data entry value.
     DOMString value;
   };
 
   dictionary UploadResult {
     // The report ID for the uploaded log. Will be empty if not successful.
     DOMString reportId;
   };
 
   dictionary RequestInfo {
     // The tab identifier from the chrome.tabs API, if the request is from a
     // tab.
     long? tabId;
 
     // The guest process id for the requester, if the request is from a
     // webview.
     long? guestProcessId;
   };
+  
+  // This contains information about the result of an audio debug recordings.

[Marijn Kruisselbrink, 2015/12/18 23:40:10]

"an recordings" is not a thing. Either make it singular or get rid of the "an".

[Guido Urdaneta, 2015/12/19 00:32:42]

Done.

+  dictionary AudioDebugRecordingsInfo {

[Marijn Kruisselbrink, 2015/12/18 23:40:10]

AudioDebugRecordings sounds really weird to me. Is there a reason it is plural
Recordings?

[Guido Urdaneta, 2015/12/19 00:32:42]

The underlying mechanism this is based on uses plural
(RenderProcessHost::EnableAudioDebugRecordings()).
The reason it's plural is that it creates separate recording files for each
active WebRTC peer connection, and, in addition to that, there are multiple
recordings for each peer connection (e.g., audio before and after applying echo
cancellation).

+    // Absolute path prefix for the files with the audio debug recordings.
+    DOMString prefixPath;
+    
+    // Indicates if recording was stopped. 
+    boolean didStop;
+    
+    // Indicates if recording was stopped manually through a 
+    // stopAudioDebugRecordings() call.
+    boolean didManualStop;
+  };
+
 
   callback GenericDoneCallback = void ();
+  callback AudioDebugRecordingsCallback = 
+      void (AudioDebugRecordingsInfo info);
   callback UploadDoneCallback = void (UploadResult result);
 
   interface Functions {
     // For all functions, |request| determines which render process to apply
     // the operation on. |request| identifies the requesting process.
     // |securityOrigin| is the security origin for the tab identified by |tabId|
     // and is used for verifying that the tab is the correct one and has not
     // been navigated away from.
 
     // Sets additional custom meta data that will be uploaded along with the
@@ skipping 62 matching lines @@
                              GenericDoneCallback callback);
 
     // Stops RTP dumping. After stop has finished, the dumps will be
     // uploaded with the log if upload is called. Otherwise, the dumps will be
     // discarded.
     static void stopRtpDump(RequestInfo request,
                             DOMString securityOrigin,
                             boolean incoming,
                             boolean outgoing,
                             GenericDoneCallback callback);
+
+    // Starts audio debug recordings. 
+    // |seconds| indicates how many seconds of audio to record. |callback| 
+    // is invoked once recording stops.
+    // If |seconds| is zero, recording will continue until 
+    // stopAudioDebugRecordings() is explicitly called. In this case, 
+    // |callback| is not invoked.

[Marijn Kruisselbrink, 2015/12/18 23:40:10]

If |callback| is only sometimes invoked, how do you make sure extension
internals don't indefinitely hold on to a reference to this callback?

[Guido Urdaneta, 2015/12/19 00:32:42]

Fixed the comment. I had fixed this in the code, but forgot to update the
comment.

+    // If |seconds| is negative, startAudioDebugRecordings() fails.
+    static void startAudioDebugRecordings(RequestInfo request,
+                             DOMString securityOrigin,
+                             long seconds, 
+                             AudioDebugRecordingsCallback callback);
+
+    // Stops audio debug recordings.  |callback| is invoked once recording 
+    // stops. If there is no recordig in progress, stopAudioDebugRecordings()
+    // fails.  
+    static void stopAudioDebugRecordings(RequestInfo request,
+                            DOMString securityOrigin,
+                            AudioDebugRecordingsCallback callback);
   };
 };