Adds MediaClientAndroid to support embedder/MediaDrmBridge interaction.

media/base/android/media_client_android.h

+// Copyright 2015 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_ANDROID_MEDIA_CLIENT_ANDROID_H_
+#define MEDIA_BASE_ANDROID_MEDIA_CLIENT_ANDROID_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/macros.h"
+#include "media/base/media_export.h"
+
+namespace media {
+
+class MediaDrmBridgeDelegate;
+class MediaClientAndroid;

[xhwang, 2015/04/24 04:52:23]

nit: order

[gunsch, 2015/04/27 23:44:12]

Done.

+
+// Setter for MediaClientAndroid. This should be called early in embedder
+// lifecycle, before any media playback could occur.
+MEDIA_EXPORT void SetMediaClientAndroid(MediaClientAndroid* media_client);
+
+#if defined(MEDIA_IMPLEMENTATION)
+// Getter for the client. Returns nullptr if no customized client is needed.
+MediaClientAndroid* GetMediaClientAndroid();
+#endif
+
+// A client interface for embedders (e.g. content/browser) to provide customized
+// additions to Android's browser-side media handling.
+class MEDIA_EXPORT MediaClientAndroid {
+ public:
+  MediaClientAndroid();
+  virtual ~MediaClientAndroid();
+
+  // Returns extra mappings from key-system name to Android UUID.
+  virtual std::vector<std::pair<std::string, std::vector<uint8_t>>>

[xhwang, 2015/04/24 04:52:23]

How about:

using UUID = std::vector<uint8_t>;

using UUIDMapping = std::vector<std::pair<std::string, UUID>>

Actually, why this can't be a std::map or hash map?

[gunsch, 2015/04/27 23:44:12]

Done.

+      GetKeySystemUUIDMappings() const;

[xhwang, 2015/04/24 04:52:23]

Returning a vector of string/vector involves copy which is expensive. Can we
return a reference since all implementations have the mapping a member variable?

[gunsch, 2015/04/27 23:44:12]

Not all implementations do, see the default MediaClientAndroid implementation.

Though, it seems like a good enough idea that I've reworked to have:
* MediaClientAndroid base class create its own map (it already needs one anyways
if it's going to return a const ref)
* Make GetKeySystemUUIDMappings non-overridable
* Provide a protected method for implementations to add mappings to the base
class

Now implementations aren't required to worry about how this value is returned.

+  // Returns a MediaDrmBridgeDelegate
+  virtual media::MediaDrmBridgeDelegate* GetMediaDrmBridgeDelegate(
+      const std::vector<uint8_t>& scheme_uuid) const;

[xhwang, 2015/04/24 04:52:23]

If you follow the comment about, you can s/std::vector<unt8_t>/UUID/ here

[gunsch, 2015/04/27 23:44:12]

Done.

+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MediaClientAndroid);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_ANDROID_MEDIA_CLIENT_ANDROID_H_