media: Add DefaultMediaPermission.

mojo/services/html_viewer/html_document.h

Index: mojo/services/html_viewer/html_document.h
diff --git a/mojo/services/html_viewer/html_document.h b/mojo/services/html_viewer/html_document.h
index eedfc06e017714a1323488c9a05e52e549e02ef2..f5b439e6f23fb9c54effe4e3d0f97ce1653ca4a8 100644
--- a/mojo/services/html_viewer/html_document.h
+++ b/mojo/services/html_viewer/html_document.h
@@ -30,6 +30,7 @@ class MessageLoopProxy;
 }
 
 namespace media {
+class MediaPermission;
 class WebEncryptedMediaClientImpl;
 }
 
@@ -139,6 +140,7 @@ class HTMLDocument : public blink::WebViewClient,
 
   // EncryptedMediaClient attached to this frame; lazily initialized.
   scoped_ptr<media::WebEncryptedMediaClientImpl> web_encrypted_media_client_;
+  scoped_ptr<media::MediaPermission> media_permission_;
 
   // HTMLDocument owns these pointers.
   std::set<AxProviderImpl*> ax_provider_impls_;