Use nullptr instead of 0 in WebAudio

Source/platform/audio/HRTFPanner.cpp

Index: Source/platform/audio/HRTFPanner.cpp
diff --git a/Source/platform/audio/HRTFPanner.cpp b/Source/platform/audio/HRTFPanner.cpp
index 4c47c1ab7ae0e51f6a350f11e7d687e7fdb2edf8..7ad2d6435b26a0db7ce68a6a0b6aa791696ecc19 100644
--- a/Source/platform/audio/HRTFPanner.cpp
+++ b/Source/platform/audio/HRTFPanner.cpp
@@ -160,7 +160,7 @@ void HRTFPanner::pan(double desiredAzimuth, double elevation, const AudioBus* in
     // Normally, we'll just be dealing with mono sources.
     // If we have a stereo input, implement stereo panning with left source processed by left HRTF, and right source by right HRTF.
     const AudioChannel* inputChannelL = inputBus->channelByType(AudioBus::ChannelLeft);
-    const AudioChannel* inputChannelR = numInputChannels > 1 ? inputBus->channelByType(AudioBus::ChannelRight) : 0;
+    const AudioChannel* inputChannelR = numInputChannels > 1 ? inputBus->channelByType(AudioBus::ChannelRight) : nullptr;
 
     // Get source and destination pointers.
     const float* sourceL = inputChannelL->data();