Media Capabilities: add plumbing between Blink and media/blink/.

third_party/WebKit/public/platform/modules/media_capabilities/WebMediaConfiguration.h

+// Copyright 2017 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 WebMediaConfiguration_h
+#define WebMediaConfiguration_h
+
+#include "base/optional.h"
+#include "public/platform/modules/media_capabilities/WebAudioConfiguration.h"
+#include "public/platform/modules/media_capabilities/WebVideoConfiguration.h"
+
+namespace blink {
+
+enum class MediaConfigurationType {
+  File,
+  MediaSource,
+};
+
+// Represents a MediaConfiguration dictionary to be used outside of Blink. At
+// least one of `audioConfiguration` or `videoConfiguration` will be set.
+// It is created by Blink and passed to consumers that can assume that all
+// required fields are properly set.
+struct WebMediaConfiguration {
+  MediaConfigurationType type;
+
+  base::Optional<WebAudioConfiguration> audioConfiguration;
+  base::Optional<WebVideoConfiguration> videoConfiguration;
+};
+
+}  // namespace blink
+
+#endif  // WebMediaConfiguration_h