[Presentation API] Add support for multiple URLs in PresentationRequest on Media Router UI side

chrome/browser/ui/webui/media_router/cast_modes_with_media_sources.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 CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_CAST_MODES_WITH_MEDIA_SOURCES_H_
+#define CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_CAST_MODES_WITH_MEDIA_SOURCES_H_
+
+#include <map>
+#include <unordered_set>
+
+#include "chrome/browser/media/router/media_source.h"
+#include "chrome/browser/ui/webui/media_router/media_cast_mode.h"
+
+namespace media_router {
+
+// Contains information on cast modes and the sources associated with them.
+// Each cast mode contained has at least one source.
+class CastModesWithMediaSources {
+ public:
+  CastModesWithMediaSources();
+  CastModesWithMediaSources(const CastModesWithMediaSources& other);
+  ~CastModesWithMediaSources();
+
+  // Add a source for the cast mode.
+  void AddSource(const MediaSource& source, MediaCastMode cast_mode);

[mark a. foltz, 2016/09/02 23:00:37]

Nit: the mapping is from cast mode to source(s).  I would reverse the order of
the arguments here and below.

[takumif, 2016/09/06 21:53:20]

Done.

+
+  // Remove a source from the cast mode. The cast mode will also get removed if
+  // it has no other sources. This is a no-op if the source is not found.
+  void RemoveSource(const MediaSource& source, MediaCastMode cast_mode);
+
+  // Returns true if the source for the cast mode is contained.
+  bool HasSource(const MediaSource& source, MediaCastMode cast_mode) const;
+
+  // Returns a set of all the cast modes contained.
+  CastModeSet GetCastModes() const;
+
+  // Returns true if there are no cast modes contained.

[mark a. foltz, 2016/09/02 23:00:37]

Not sure this adds much versus GetCastModes().empty().

[takumif, 2016/09/06 21:53:20]

It's more obvious than GetCastModes().empty(), and we'll only have to fix it
here if we ever decide to stop using CastModeSet::empty().

+  bool IsEmpty() const;
+
+ private:
+  std::map<MediaCastMode, std::unordered_set<MediaSource, MediaSource::Hash>>

[mark a. foltz, 2016/09/02 23:00:37]

A std::multimap may be simpler but would not inherently enforce uniqueness of
MediaSource per MediaCastMode, which seems like a good property.

[takumif, 2016/09/06 21:53:20]

Yeah, it's nice not having to check for duplicates when adding. And removing a
source would be a bit more complicated.

+  cast_modes_;
+};
+
+}  // namespace media_router
+
+#endif  // CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_CAST_MODES_WITH_MEDIA_SOURCES_H_