media: Make MediaKeys ref-counted.

chromecast/media/cdm/browser_cdm_cast.h

Index: chromecast/media/cdm/browser_cdm_cast.h
diff --git a/chromecast/media/cdm/browser_cdm_cast.h b/chromecast/media/cdm/browser_cdm_cast.h
index a4c80fb748a8a078d9a07cf80c9e3c6814b0f7b5..074d286890bf3b2f9c24ffc063ab03f708397b2b 100644
--- a/chromecast/media/cdm/browser_cdm_cast.h
+++ b/chromecast/media/cdm/browser_cdm_cast.h
@@ -14,8 +14,10 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner_helpers.h"
 #include "base/threading/thread_checker.h"
-#include "media/base/browser_cdm.h"
+#include "media/base/media_keys.h"
+#include "media/base/player_tracker.h"
 #include "media/cdm/json_web_key.h"
 
 namespace base {
@@ -30,17 +32,17 @@ namespace chromecast {
 namespace media {
 class DecryptContextImpl;
 
-// BrowserCdmCast is an extension of BrowserCdm that provides common
+// BrowserCdmCast is an extension of MediaKeys that provides common
 // functionality across CDM implementations.
 // All these additional functions are synchronous so:
 // - either both the CDM and the media pipeline must be running on the same
 //   thread,
 // - or BrowserCdmCast implementations must use some locks.
 //
-class BrowserCdmCast : public ::media::BrowserCdm {
+class BrowserCdmCast : public ::media::MediaKeys,
+                       public ::media::PlayerTracker {
  public:
   BrowserCdmCast();
-  ~BrowserCdmCast() override;
 
   void Initialize(
       const ::media::SessionMessageCB& session_message_cb,
@@ -49,12 +51,12 @@ class BrowserCdmCast : public ::media::BrowserCdm {
       const ::media::SessionKeysChangeCB& session_keys_change_cb,
       const ::media::SessionExpirationUpdateCB& session_expiration_update_cb);
 
-  // PlayerTracker implementation.
+  // ::media::PlayerTracker implementation.
   int RegisterPlayer(const base::Closure& new_key_cb,
                      const base::Closure& cdm_unset_cb) override;
   void UnregisterPlayer(int registration_id) override;
 
-  // ::media::BrowserCdm implementation:
+  // ::media::MediaKeys implementation:
   ::media::CdmContext* GetCdmContext() override;
 
   // Returns the decryption context needed to decrypt frames encrypted with
@@ -75,6 +77,8 @@ class BrowserCdmCast : public ::media::BrowserCdm {
  private:
   friend class BrowserCdmCastUi;
 
+  ~BrowserCdmCast() override;
+
   // Allow subclasses to override to provide key sysytem specific
   // initialization.
   virtual void InitializeInternal();
@@ -92,24 +96,22 @@ class BrowserCdmCast : public ::media::BrowserCdm {
   DISALLOW_COPY_AND_ASSIGN(BrowserCdmCast);
 };
 
-// BrowserCdm implementation that lives on the UI thread and forwards all calls
+// MediaKeys implementation that lives on the UI thread and forwards all calls
 // to a BrowserCdmCast instance on the CMA thread. This is used to simplify the
 // UI-CMA threading interaction.
-class BrowserCdmCastUi : public ::media::BrowserCdm {
+class BrowserCdmCastUi : public ::media::MediaKeys {
  public:
   BrowserCdmCastUi(
-      scoped_ptr<BrowserCdmCast> browser_cdm_cast,
+      const scoped_refptr<BrowserCdmCast>& browser_cdm_cast,
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
-  ~BrowserCdmCastUi() override;
-
-  // PlayerTracker implementation:
-  int RegisterPlayer(const base::Closure& new_key_cb,
-                     const base::Closure& cdm_unset_cb) override;
-  void UnregisterPlayer(int registration_id) override;
 
   BrowserCdmCast* browser_cdm_cast() const;
 
  private:
+  // For DeleteSoon() in DeleteOnCorrectThread().
+  friend class base::DeleteHelper<BrowserCdmCastUi>;
+  ~BrowserCdmCastUi() override;
+
   // ::media::MediaKeys implementation:
   void SetServerCertificate(
       const std::vector<uint8_t>& certificate,
@@ -130,8 +132,9 @@ class BrowserCdmCastUi : public ::media::BrowserCdm {
   void RemoveSession(const std::string& session_id,
                      scoped_ptr<::media::SimpleCdmPromise> promise) override;
   ::media::CdmContext* GetCdmContext() override;
+  void DeleteOnCorrectThread() const override;
 
-  scoped_ptr<BrowserCdmCast> browser_cdm_cast_;
+  scoped_refptr<BrowserCdmCast> browser_cdm_cast_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   base::ThreadChecker thread_checker_;