Bug 1456946 - Properly reflect the channelCount when set in the ctor using the option object, on a ChannelSplitterNode. r=achronop

MozReview-Commit-ID: DrnadeBS8hi

--HG--
extra : rebase_source : 8c1863f7ad21f9b4f8e41232402fdb9825e7de90

dom/media/webaudio/ChannelSplitterNode.cpp

@@ -53,7 +53,7 @@ public:
 ChannelSplitterNode::ChannelSplitterNode(AudioContext* aContext,
                                          uint16_t aOutputCount)
   : AudioNode(aContext,
-              6,
+              aOutputCount,
               ChannelCountMode::Explicit,
               ChannelInterpretation::Discrete)
   , mOutputCount(aOutputCount)