[worklets] Add AudioWorkletGlobalScope and AudioWorkletThread

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

Index: third_party/WebKit/Source/modules/webaudio/AudioWorkletGlobalScope.idl
diff --git a/third_party/WebKit/Source/modules/webaudio/AudioWorkletGlobalScope.idl b/third_party/WebKit/Source/modules/webaudio/AudioWorkletGlobalScope.idl
new file mode 100644
index 0000000000000000000000000000000000000000..f25023b9b5338b48e2762e180b261fdb18f98afd
--- /dev/null
+++ b/third_party/WebKit/Source/modules/webaudio/AudioWorkletGlobalScope.idl
@@ -0,0 +1,14 @@
+// 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.
+
+// https://webaudio.github.io/web-audio-api/#AudioWorkletGlobalScope
+
+[
+    Exposed=AudioWorklet,
+    Global=(Worklet,AudioWorklet),
+    RuntimeEnabled=AudioWorklet,
+] interface AudioWorkletGlobalScope : WorkletGlobalScope {
+    // TODO(hongchan): implement this.
+    // [RaiseException] void registerProcessor(DOMString name, Function processorCtor);
+};