PlzNavigate: Get StreamPrivate API to work.

extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.h

Index: extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.h
diff --git a/extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.h b/extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.h
index 880f140b88c952beed6bb2f05ebe5751aea77d8f..b864401242228a6638a5c36b93191bcdeceed458 100644
--- a/extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.h
+++ b/extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.h
@@ -16,6 +16,7 @@
 
 namespace content {
 class BrowserContext;
+class WebContents;
 }
 
 namespace extensions {
@@ -34,8 +35,14 @@ class MimeHandlerStreamManager : public KeyedService,
   ~MimeHandlerStreamManager() override;
   static MimeHandlerStreamManager* Get(content::BrowserContext* context);
 
+  // The |frame_tree_node_id| parameter is used for PlzNavigate for the top
+  // level plugins case. (PDF, etc). If this parameter has a valid value then
+  // it overrides the |render_process_id| and |render_frame_id| parameters.
+  // The |render_process_id| is the id of the renderer process.
+  // The |render_frame_id| is the routing id of the RenderFrameHost.
   void AddStream(const std::string& view_id,
                  std::unique_ptr<StreamContainer> stream,
+                 int frame_tree_node_id,
                  int render_process_id,
                  int render_frame_id);