Create an interface for KeySystems, migrate WebEncryptedMediaClientImpl.

media/blink/webencryptedmediaclient_impl.h

Index: media/blink/webencryptedmediaclient_impl.h
diff --git a/media/blink/webencryptedmediaclient_impl.h b/media/blink/webencryptedmediaclient_impl.h
index 36d104b4383e45df391eb6fb9c2ad29074775cdc..2e17c25c87da49401128a499d5ca89cfba4d7edd 100644
--- a/media/blink/webencryptedmediaclient_impl.h
+++ b/media/blink/webencryptedmediaclient_impl.h
@@ -18,12 +18,14 @@
 
 namespace media {
 
+class KeySystems;
 class MediaPermission;
 
 class MEDIA_EXPORT WebEncryptedMediaClientImpl
     : public blink::WebEncryptedMediaClient {
  public:
-  WebEncryptedMediaClientImpl(scoped_ptr<CdmFactory> cdm_factory,
+  WebEncryptedMediaClientImpl(const KeySystems& key_systems,
+                              scoped_ptr<CdmFactory> cdm_factory,
                               MediaPermission* media_permission);
   virtual ~WebEncryptedMediaClientImpl();
 
@@ -60,6 +62,7 @@ class MEDIA_EXPORT WebEncryptedMediaClientImpl
   typedef base::ScopedPtrHashMap<std::string, Reporter> Reporters;
   Reporters reporters_;
 
+  const KeySystems& key_systems_;
   scoped_ptr<CdmFactory> cdm_factory_;
   MediaPermission* media_permission_;