Early initialize recording on the ADM from WebRtcVoiceMediaChannel.

webrtc/media/engine/webrtcvoiceengine.cc

Index: webrtc/media/engine/webrtcvoiceengine.cc
diff --git a/webrtc/media/engine/webrtcvoiceengine.cc b/webrtc/media/engine/webrtcvoiceengine.cc
index 46119311bce328c4b47f5b139c3e776855bee855..5e7ff1a3b9429cbbdd7d8ad46dcfdfb65dcb9001 100644
--- a/webrtc/media/engine/webrtcvoiceengine.cc
+++ b/webrtc/media/engine/webrtcvoiceengine.cc
@@ -1855,9 +1855,18 @@ void WebRtcVoiceMediaChannel::SetSend(bool send) {
     return;
   }
 
-  // Apply channel specific options when channel is enabled for sending.
+  // Apply channel specific options, and initialize the ADM for recording (this
+  // may take time on some platforms, e.g. Android).
   if (send) {
     engine()->ApplyOptions(options_);
+
+    // InitRecording() may return an error if the ADM is already recording.
+    if (!engine()->adm()->RecordingIsInitialized() &&
+        !engine()->adm()->Recording()) {
+      if (engine()->adm()->InitRecording() != 0) {
+        LOG(LS_WARNING) << "Failed to initialize recording";
+      }
+    }
   }
 
   // Change the settings on each send channel.