media: Make MediaKeys ref-counted.

media/base/android/media_player_android.cc

Index: media/base/android/media_player_android.cc
diff --git a/media/base/android/media_player_android.cc b/media/base/android/media_player_android.cc
index c08c259420abe09527515d48d99dce47a7f06403..9bde3dedbd01e746678d4418cbe70428d64029de 100644
--- a/media/base/android/media_player_android.cc
+++ b/media/base/android/media_player_android.cc
@@ -42,7 +42,7 @@ GURL MediaPlayerAndroid::GetFirstPartyForCookies() {
   return GURL();
 }
 
-void MediaPlayerAndroid::SetCdm(BrowserCdm* /* cdm */) {
+void MediaPlayerAndroid::SetCdm(const scoped_refptr<MediaKeys>& /* cdm */) {
   // Players that support EME should override this.
   LOG(ERROR) << "EME not supported on base MediaPlayerAndroid class.";
   return;