Encrypted Media: Implement IPC based SetCdm().

content/common/media/media_player_messages_android.h

Index: content/common/media/media_player_messages_android.h
diff --git a/content/common/media/media_player_messages_android.h b/content/common/media/media_player_messages_android.h
index 2b2b383d97823b851b0f3ad352350e8fa32a3811..30094989c0ae9ae70e4bc4d3277f01b07978dd46 100644
--- a/content/common/media/media_player_messages_android.h
+++ b/content/common/media/media_player_messages_android.h
@@ -247,6 +247,11 @@ IPC_MESSAGE_ROUTED1(MediaPlayerHostMsg_EnterFullscreen, int /* player_id */)
 // Requests the player to exit fullscreen.
 IPC_MESSAGE_ROUTED1(MediaPlayerHostMsg_ExitFullscreen, int /* player_id */)
 
+// Requests the player with |player_id| to use the CDM with |cdm_id|.
+IPC_MESSAGE_ROUTED2(MediaPlayerHostMsg_SetMediaKeys,
+                    int /* player_id */,
+                    int /* cdm_id */);
+
 // Sent after the renderer demuxer has seeked.
 IPC_MESSAGE_CONTROL2(MediaPlayerHostMsg_DemuxerSeekDone,
                      int /* demuxer_client_id */,