Create an interface for KeySystems, migrate WebEncryptedMediaClientImpl.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index ebc42b1dc4aa30341b2ec87d98ee813fb198728e..a1604985ccf6575eabab739be60e21c4255016bd 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -104,6 +104,7 @@
 #include "content/renderer/websharedworker_proxy.h"
 #include "gin/modules/module_registry.h"
 #include "media/base/audio_renderer_mixer_input.h"
+#include "media/base/key_systems.h"
 #include "media/base/media_log.h"
 #include "media/blink/webencryptedmediaclient_impl.h"
 #include "media/blink/webmediaplayer_impl.h"
@@ -3431,7 +3432,8 @@ blink::WebEncryptedMediaClient* RenderFrameImpl::encryptedMediaClient() {
       media_permission_dispatcher_ = new MediaPermissionDispatcher(this);
 
     web_encrypted_media_client_.reset(new media::WebEncryptedMediaClientImpl(
-        cdm_factory.Pass(), media_permission_dispatcher_));
+        media::KeySystems::GetInstance(), cdm_factory.Pass(),
+        media_permission_dispatcher_));
   }
   return web_encrypted_media_client_.get();
 }