Add constructors for WebAudio nodes

third_party/WebKit/Source/modules/webaudio/AnalyserOptions.idl

Index: third_party/WebKit/Source/modules/webaudio/AnalyserOptions.idl
diff --git a/third_party/WebKit/Source/modules/webaudio/AnalyserOptions.idl b/third_party/WebKit/Source/modules/webaudio/AnalyserOptions.idl
new file mode 100644
index 0000000000000000000000000000000000000000..8825426b7140e2863f8c209dc2e6ffe733fccef5
--- /dev/null
+++ b/third_party/WebKit/Source/modules/webaudio/AnalyserOptions.idl
@@ -0,0 +1,11 @@
+// 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.
+
+// See https://webaudio.github.io/web-audio-api/#analyseroptions
+dictionary AnalyserOptions : AudioNodeOptions {
+    unsigned long fftSize = 2048;
+    float maxDecibels = -30;
+    float minDecibels = -100;
+    float smoothingTimeConstant = 0.8;
+};