Add CdmService to keep track of CDMs

content/public/common/cdm_service.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 CONTENT_PUBLIC_COMMON_CDM_SERVICE_H_
+#define CONTENT_PUBLIC_COMMON_CDM_SERVICE_H_
+
+#include <string>
+#include <vector>
+
+#include "base/files/file_path.h"
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/strings/string16.h"

[ddorwin, 2016/03/18 19:24:19]

no

[jrummell, 2016/03/23 21:38:10]

Done.

+#include "base/version.h"
+#include "content/common/content_export.h"
+#include "content/public/common/cdm_info.h"
+
+namespace content {
+
+class CONTENT_EXPORT CdmService {

[ddorwin, 2016/03/18 22:22:11]

Is this really a service or just a registry?

[xhwang, 2016/03/18 23:16:02]

Either works for me :) I guess we were following the model of PluginService.

+ public:
+  // Returns the CdmService singleton.
+  static CdmService* GetInstance();
+
+  // Registers |cdm_id|, replacing any entry that may exist for it (with

[xhwang, 2016/03/18 19:35:38]

ditto about cdm_id

[jrummell, 2016/03/23 21:38:10]

Done.

+  // same |version|). |module_library_path| is the path to the actual CDM

[ddorwin, 2016/03/18 19:24:19]

Do we expect this to be called multiple times with the same version? I would
hope not. It seems simpler to just always insert.

[jrummell, 2016/03/23 21:38:10]

Done.

+  // (may be empty if the CDM is already included as part of the system),

[ddorwin, 2016/03/18 19:24:19]

ditto on the ifdef.

[jrummell, 2016/03/23 21:38:10]

No longer an issue here.

+  // and |supported_codecs| and |supported_init_data_types| are the list
+  // of codecs, and the list of init_data_types, respectively, supported
+  // by this CDM (which may be none).
+  void Register(const std::string& cdm_id,

[ddorwin, 2016/03/18 19:24:19]

nit: RegisterCdm seems better. WDYT?

[jrummell, 2016/03/23 21:38:10]

Done.

+                const std::string& version,
+                const base::FilePath& module_library_path,
+                const std::vector<base::string16>& supported_codecs,
+                const std::vector<base::string16>& supported_init_data_types);

[xhwang, 2016/03/18 19:35:38]

It seems content APIs should be pure abstract:

https://www.chromium.org/developers/content-module/content-api

Maybe this file should be a pure interface and we should put the implementations
in another file.

[jrummell, 2016/03/23 21:38:10]

Done (by moving this file and matching what is done for plugins).

+
+  // Returns the list of all registered CDMs and the associated data.
+  // Paths in |key_systems| may be empty if the CDM is already included as

[ddorwin, 2016/03/18 19:24:19]

Seems unnecessary. This is already covered in the CdmInfo definition.

[jrummell, 2016/03/23 21:38:10]

Done.

+  // part of the system.
+  const std::vector<CdmInfo>& GetAllRegisteredCdms() const;

[xhwang, 2016/03/18 19:35:38]

For interfaces we don't use "const":

https://www.chromium.org/developers/content-module/content-api

[jrummell, 2016/03/23 21:38:10]

Done.

+
+ private:
+  friend struct base::DefaultLazyInstanceTraits<CdmService>;
+
+  CdmService();
+  ~CdmService();
+
+  std::vector<CdmInfo> registered_modules_;

[ddorwin, 2016/03/18 19:24:18]

"modules" is first used alone here. "cdms" seems better. or just |cdms_|.

[jrummell, 2016/03/23 21:38:10]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(CdmService);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_COMMON_CDM_SERVICE_H_