Implement IIRFilter node for WebAudio.

third_party/WebKit/Source/modules/webaudio/IIRFilterNode.h

Index: third_party/WebKit/Source/modules/webaudio/IIRFilterNode.h
diff --git a/third_party/WebKit/Source/modules/webaudio/IIRFilterNode.h b/third_party/WebKit/Source/modules/webaudio/IIRFilterNode.h
new file mode 100644
index 0000000000000000000000000000000000000000..5bfc54203cc4af30227d5e4da5f73df5570efce6
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+++ b/third_party/WebKit/Source/modules/webaudio/IIRFilterNode.h
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+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IIRFilterNode_h
+#define IIRFilterNode_h
+
+#include "core/dom/DOMTypedArray.h"
+#include "modules/webaudio/AudioNode.h"
+#include "modules/webaudio/IIRProcessor.h"
+
+namespace blink {
+
+class AbstractAudioContext;
+class ExceptionState;
+
+class IIRFilterNode : public AudioNode {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    static IIRFilterNode* create(AbstractAudioContext& context, float sampleRate, const Vector<double> feedforward, const Vector<double> feedback)
+    {
+        return new IIRFilterNode(context, sampleRate, feedforward, feedback);
+    }
+    DECLARE_VIRTUAL_TRACE();
+
+    // Get the magnitude and phase response of the filter at the given
+    // set of frequencies (in Hz). The phase response is in radians.
+    void getFrequencyResponse(const DOMFloat32Array* frequencyHz, DOMFloat32Array* magResponse, DOMFloat32Array* phaseResponse, ExceptionState&);
+
+private:
+    IIRFilterNode(AbstractAudioContext&, float sampleRate, const Vector<double> denominator, const Vector<double> numerator);
+
+    IIRProcessor* iirProcessor() const;
+};
+
+}
+
+#endif // IIRFilterNode_h