Output silence if the MediaElementAudioSourceNode has a different origin

Source/modules/webaudio/AudioContext.h

Index: Source/modules/webaudio/AudioContext.h
diff --git a/Source/modules/webaudio/AudioContext.h b/Source/modules/webaudio/AudioContext.h
index 7776cf15dade63759ee8fccb64a3720992fe0fef..ca8a882dc9fc9f0baf5f4810ccf1e8beb2ecb112 100644
--- a/Source/modules/webaudio/AudioContext.h
+++ b/Source/modules/webaudio/AudioContext.h
@@ -70,6 +70,7 @@ class OscillatorNode;
 class PannerNode;
 class PeriodicWave;
 class ScriptProcessorNode;
+class SecurityOrigin;
 class StereoPannerNode;
 class WaveShaperNode;
 
@@ -267,6 +268,9 @@ public:
 
     static unsigned s_hardwareContextCount;
 
+    // Get the security origin for this audio context.
+    SecurityOrigin* securityOrigin() const;
+
 protected:
     explicit AudioContext(Document*);
     AudioContext(Document*, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate);