Support for AudioContextOptions latencyHint.

third_party/WebKit/public/platform/WebAudioLatencyHint.h

+// 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 WebAudioLatencyHint_h
+#define WebAudioLatencyHint_h
+
+#include "WebString.h"
+
+namespace blink {
+
+class WebAudioLatencyHint {
+ public:
+  enum Category { CategoryInteractive, CategoryBalanced, CategoryPlayback };
+
+  explicit WebAudioLatencyHint(WebString category) {
+    if (category == "interactive") {
+      m_category = CategoryInteractive;
+    } else if (category == "balanced") {
+      m_category = CategoryBalanced;
+    } else if (category == "playback") {
+      m_category = CategoryPlayback;
+    } else {
+      NOTREACHED();
+      m_category = CategoryInteractive;
+    }
+  }
+
+  explicit WebAudioLatencyHint(Category category) : m_category(category) {}
+
+  Category category() const { return m_category; }
+
+ private:
+  Category m_category;
+};
+
+}  // namespace blink
+
+#endif