Add CdmService to keep track of CDMs

content/public/browser/cdm_service.h

Index: content/public/browser/cdm_service.h
diff --git a/content/public/browser/cdm_service.h b/content/public/browser/cdm_service.h
new file mode 100644
index 0000000000000000000000000000000000000000..501970ea54e0d35cf982f0d7a7bc857a571e3780
--- /dev/null
+++ b/content/public/browser/cdm_service.h
@@ -0,0 +1,41 @@
+// 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_BROWSER_CDM_SERVICE_H_
+#define CONTENT_PUBLIC_BROWSER_CDM_SERVICE_H_
+
+#include <vector>
+
+#include "content/common/content_export.h"
+
+namespace content {
+
+struct CdmInfo;
+

[no sievers, 2016/04/18 21:24:21]

Can you also put a small comment, at least saying what 'CDM' stands for, and
what a CDM service is?

[jrummell, 2016/04/19 23:20:39]

Done.

+class CONTENT_EXPORT CdmService {
+ public:
+  // Returns the CdmService singleton.
+  static CdmService* GetInstance();
+
+  virtual ~CdmService() {}
+
+  // Must be called on the instance to finish initialization.
+  virtual void Init() = 0;
+
+  // Registers a CDM with the specified CDM information. The CDM will be
+  // inserted at the head of the list so that it can override any older
+  // registrations.
+  // Note: Since only 1 version of the CDM can be loaded at any given time,
+  // it is possible that there will be a mismatch between the functionality
+  // reported and what is actually available, if the reported functionality
+  // changes between versions. (http://crbug.com/599588)
+  virtual void RegisterCdm(const CdmInfo& info) = 0;
+

[no sievers, 2016/04/18 21:24:21]

Hmm it's a bit confusing that there are two APIs to add CDMs (this one and the
ContentClient callback). Why do we need both?

[jrummell, 2016/04/19 23:20:39]

Widevine (the only CDM supported with Chrome) is updated via the component
updater on Win/Mac, bundled on Linux, and included as part of Android and Cast.
So we need a way for embedders to register CDMs as well as the component
updater.

[no sievers, 2016/04/20 00:03:35]

But I'm wondering why you need two public APIs. It's just a bit confusing,

+  // Returns the list of all registered CDMs and the associated data.
+  virtual const std::vector<CdmInfo>& GetAllRegisteredCdms() const = 0;

[no sievers, 2016/04/18 21:24:21]

Make this method non-const, see reasoning here:
https://www.chromium.org/developers/content-module/content-api

[jrummell, 2016/04/19 23:20:39]

Done.

+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_CDM_SERVICE_H_