Fix threading races on ConvolverNode::m_reverb in ConvolverNode::tailTime()

Source/modules/webaudio/ConvolverNode.cpp

Index: Source/modules/webaudio/ConvolverNode.cpp
diff --git a/Source/modules/webaudio/ConvolverNode.cpp b/Source/modules/webaudio/ConvolverNode.cpp
index 36a473f5f4f58cc6649a429c2af5f1f7903032cf..fcea79f64ca104fcf50c8591aea69b1390de7455 100644
--- a/Source/modules/webaudio/ConvolverNode.cpp
+++ b/Source/modules/webaudio/ConvolverNode.cpp
@@ -158,7 +158,12 @@ AudioBuffer* ConvolverNode::buffer()
 
 double ConvolverNode::tailTime() const
 {
-    return m_reverb ? m_reverb->impulseResponseLength() / static_cast<double>(sampleRate()) : 0;
+    MutexTryLocker tryLocker(m_processLock);
+    if (tryLocker.locked())
+        return m_reverb ? m_reverb->impulseResponseLength() / static_cast<double>(sampleRate()) : 0;
+    // Since we don't want to block the Audio Device thread, we return a large value
+    // instead of trying to acquire the lock.
+    return std::numeric_limits<double>::infinity();
 }
 
 double ConvolverNode::latencyTime() const