media: Make MediaKeys ref-counted.

media/base/android/media_codec_player.h

Index: media/base/android/media_codec_player.h
diff --git a/media/base/android/media_codec_player.h b/media/base/android/media_codec_player.h
index 376c2e4f94472a0c8f749227acac84c972b6d7ca..669670119e90db4a617cb52cd38b4ae341f26163 100644
--- a/media/base/android/media_codec_player.h
+++ b/media/base/android/media_codec_player.h
@@ -157,7 +157,6 @@
 
 namespace media {
 
-class BrowserCdm;
 class MediaCodecAudioDecoder;
 class MediaCodecVideoDecoder;
 
@@ -214,7 +213,7 @@ class MEDIA_EXPORT MediaCodecPlayer : public MediaPlayerAndroid,
   bool CanSeekForward() override;
   bool CanSeekBackward() override;
   bool IsPlayerReady() override;
-  void SetCdm(BrowserCdm* cdm) override;
+  void SetCdm(const scoped_refptr<MediaKeys>& cdm) override;
 
   // DemuxerAndroidClient implementation.
   void OnDemuxerConfigsAvailable(const DemuxerConfigs& params) override;
@@ -300,7 +299,7 @@ class MEDIA_EXPORT MediaCodecPlayer : public MediaPlayerAndroid,
   // Callbacks from video decoder
   void OnVideoResolutionChanged(const gfx::Size& size);
 
-  // Callbacks from CDM
+  // Callbacks from MediaDrmBridge.
   void OnMediaCryptoReady(MediaDrmBridge::JavaObjectPtr media_crypto,
                           bool needs_protected_surface);
   void OnKeyAdded();
@@ -395,7 +394,10 @@ class MEDIA_EXPORT MediaCodecPlayer : public MediaPlayerAndroid,
   // For testing only.
   DecodersTimeCallback decoders_time_cb_;
 
-  // DRM
+  // Holds a ref-count to the CDM to keep |media_crypto_| and |drm_bridge_|
+  // valid. Reset during destruction or when the CDM is unset.
+  scoped_refptr<MediaKeys> cdm_;
+
   MediaDrmBridge::JavaObjectPtr media_crypto_;
 
   MediaDrmBridge* drm_bridge_;