Bug 1456266 - In ConstantSourceNode change the default channelCount to align with the spec. r=padenot

MozReview-Commit-ID: 9cvAztPuZic

--HG--
extra : rebase_source : 5c1ce2f40ca199ac5dda174155c74e5212225aa4

dom/media/webaudio/ConstantSourceNode.cpp

@@ -146,7 +146,7 @@ public:
 
 ConstantSourceNode::ConstantSourceNode(AudioContext* aContext)
   : AudioScheduledSourceNode(aContext,
-                             1,
+                             2,
                              ChannelCountMode::Max,
                              ChannelInterpretation::Speakers)
   , mOffset(new AudioParam(this, ConstantSourceNodeEngine::OFFSET,

testing/web-platform/meta/webaudio/the-audio-api/the-constantsourcenode-interface/constant-source-basic.html.ini

@@ -1,17 +1,11 @@
 [constant-source-basic.html]
-  [X Factory method: node.channelCount is not equal to 2. Got 1.]
-    expected: FAIL
-
   [X Factory method: node.offset.minValue is not equal to -3.4028234663852886e+38. Got -Infinity.]
     expected: FAIL
 
   [X Factory method: node.offset.maxValue is not equal to 3.4028234663852886e+38. Got Infinity.]
     expected: FAIL
 
-  [< [createConstantSource()\] 3 out of 11 assertions were failed.]
-    expected: FAIL
-
-  [X Constructor: node.channelCount is not equal to 2. Got 1.]
+  [< [createConstantSource()\] 2 out of 11 assertions were failed.]
     expected: FAIL
 
   [X Constructor: node.offset.minValue is not equal to -3.4028234663852886e+38. Got -Infinity.]
@@ -20,7 +14,7 @@
   [X Constructor: node.offset.maxValue is not equal to 3.4028234663852886e+38. Got Infinity.]
     expected: FAIL
 
-  [< [new ConstantSourceNode()\] 3 out of 11 assertions were failed.]
+  [< [new ConstantSourceNode()\] 2 out of 11 assertions were failed.]
     expected: FAIL
 
   [X start(-1) threw "NotSupportedError" instead of RangeError.]