Make WebAudio output as stereo as default.

NOTRY=true

Review URL: https://codereview.chromium.org/210713005

git-svn-id: svn://svn.chromium.org/blink/trunk@169964 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/modules/webaudio/AudioContext.cpp

@@ -418,9 +418,8 @@ PassRefPtr<MediaStreamAudioSourceNode> AudioContext::createMediaStreamSource(Med
 
 PassRefPtr<MediaStreamAudioDestinationNode> AudioContext::createMediaStreamDestination()
 {
-    // FIXME: Add support for an optional argument which specifies the number of channels.
-    // FIXME: The default should probably be stereo instead of mono.
-    return MediaStreamAudioDestinationNode::create(this, 1);
+    // Set number of output channels to stereo by default.
+    return MediaStreamAudioDestinationNode::create(this, 2);
 }
 
 PassRefPtr<ScriptProcessorNode> AudioContext::createScriptProcessor(ExceptionState& exceptionState)