Add RendererFactorySelector

media/base/renderer_factory_selector.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 MEDIA_BASE_RENDERER_FACTORY_SELECTOR_H_
+#define MEDIA_BASE_RENDERER_FACTORY_SELECTOR_H_
+
+#include "base/optional.h"
+#include "media/base/renderer_factory.h"
+
+namespace media {
+
+// RendererFactorySelector owns RendererFactory instances used within WMPI.
+// Its purpose is to aggregate the signals and centralize the logic behind
+// choosing which RendererFactory should be used when creating a new Renderer.
+class MEDIA_EXPORT RendererFactorySelector {
+ public:
+  enum FactoryType {
+    DEFAULT,       // DefaultRendererFactory.
+    MOJO,          // MojoRendererFactory.
+    MEDIA_PLAYER,  // MediaPlayerRendererClientFactory.
+    ADAPTIVE,      // AdaptiveRendererFactory.
+    FACTORY_TYPE_MAX = ADAPTIVE,
+  };
+
+  RendererFactorySelector();
+  ~RendererFactorySelector();
+
+  // NOTE: There should be at most one factory per factory type.
+  void AddFactory(FactoryType type, std::unique_ptr<RendererFactory> factory);
+
+  // Sets the base factory to be returned, when there are no signals telling us
+  // to select any specific factory.
+  // NOTE: |type| can be different than FactoryType::DEFAULT. DEFAULT is used to
+  // identify the DefaultRendererFactory, not to indicate that a factory should
+  // be used by default.
+  void SetBaseFactoryType(FactoryType type);
+
+  // SetBaseFactoryType() must be called before calling this method.
+  // NOTE: This only returns the base factory type at the moment.
+  RendererFactory* GetCurrentFactory();
+
+ private:
+  base::Optional<FactoryType> base_factory_type_;
+  std::unique_ptr<RendererFactory> factories_[FACTORY_TYPE_MAX + 1];
+  DISALLOW_COPY_AND_ASSIGN(RendererFactorySelector);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_RENDERER_FACTORY_H_