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diff --git a/Source/WebCore/webaudio/ConvolverNode.cpp b/Source/WebCore/webaudio/ConvolverNode.cpp
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+/*
+ * Copyright (C) 2010, Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1.  Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#if ENABLE(WEB_AUDIO)
+
+#include "ConvolverNode.h"
+
+#include "AudioBuffer.h"
+#include "AudioNodeInput.h"
+#include "AudioNodeOutput.h"
+#include "Reverb.h"
+
+// Note about empirical tuning:
+// The maximum FFT size affects reverb performance and accuracy.
+// If the reverb is single-threaded and processes entirely in the real-time audio thread,
+// it's important not to make this too high.  In this case 8192 is a good value.
+// But, the Reverb object is multi-threaded, so we want this as high as possible without losing too much accuracy.
+// Very large FFTs will have worse phase errors.  Given these constraints 16384 is a good compromise.
+const size_t MaxFFTSize = 16384;
+
+namespace WebCore {
+
+ConvolverNode::ConvolverNode(AudioContext* context, double sampleRate)
+    : AudioNode(context, sampleRate)
+{
+    addInput(adoptPtr(new AudioNodeInput(this)));
+    addOutput(adoptPtr(new AudioNodeOutput(this, 2)));
+    
+    setType(NodeTypeConvolver);
+    
+    initialize();
+}
+
+ConvolverNode::~ConvolverNode()
+{
+    uninitialize();
+}
+
+void ConvolverNode::process(size_t framesToProcess)
+{
+    AudioBus* outputBus = output(0)->bus();
+    ASSERT(outputBus);
+
+    // Synchronize with possible dynamic changes to the impulse response.
+    if (m_processLock.tryLock()) {
+        if (!isInitialized() || !m_reverb.get())
+            outputBus->zero();
+        else {
+            // Process using the convolution engine.
+            // Note that we can handle the case where nothing is connected to the input, in which case we'll just feed silence into the convolver.
+            // FIXME:  If we wanted to get fancy we could try to factor in the 'tail time' and stop processing once the tail dies down if
+            // we keep getting fed silence.
+            m_reverb->process(input(0)->bus(), outputBus, framesToProcess);
+        }
+        
+        m_processLock.unlock();
+    } else {
+        // Too bad - the tryLock() failed.  We must be in the middle of setting a new impulse response.
+        outputBus->zero();
+    }
+}
+
+void ConvolverNode::reset()
+{
+    MutexLocker locker(m_processLock);
+    if (m_reverb.get())
+        m_reverb->reset();
+}
+
+void ConvolverNode::initialize()
+{
+    if (isInitialized())
+        return;
+        
+    AudioNode::initialize();
+}
+
+void ConvolverNode::uninitialize()
+{
+    if (!isInitialized())
+        return;
+
+    m_reverb.clear();
+    AudioNode::uninitialize();
+}
+
+void ConvolverNode::setBuffer(AudioBuffer* buffer)
+{
+    ASSERT(isMainThread());
+    
+    ASSERT(buffer);
+    if (!buffer)
+        return;
+
+    unsigned numberOfChannels = buffer->numberOfChannels();
+    size_t bufferLength = buffer->length();
+
+    // The current implementation supports up to four channel impulse responses, which are interpreted as true-stereo (see Reverb class).
+    bool isBufferGood = numberOfChannels > 0 && numberOfChannels <= 4 && bufferLength;
+    ASSERT(isBufferGood);
+    if (!isBufferGood)
+        return;
+
+    // Wrap the AudioBuffer by an AudioBus. It's an efficient pointer set and not a memcpy().
+    // This memory is simply used in the Reverb constructor and no reference to it is kept for later use in that class.
+    AudioBus bufferBus(numberOfChannels, bufferLength, false);
+    for (unsigned i = 0; i < numberOfChannels; ++i)
+        bufferBus.setChannelMemory(i, buffer->getChannelData(i)->data(), bufferLength);
+    
+    // Create the reverb with the given impulse response.
+    OwnPtr<Reverb> reverb = adoptPtr(new Reverb(&bufferBus, AudioNode::ProcessingSizeInFrames, MaxFFTSize, 2, true));
+
+    {
+        // Synchronize with process().
+        MutexLocker locker(m_processLock);
+        m_reverb = reverb.release();
+        m_buffer = buffer;
+    }
+}
+
+AudioBuffer* ConvolverNode::buffer()
+{
+    ASSERT(isMainThread());
+    return m_buffer.get();
+}
+
+} // namespace WebCore
+
+#endif // ENABLE(WEB_AUDIO)