[OLD ATTEMPT, DO NOT REVIEW] mustash: Enable connections to mus from the Chrome renderer

content/public/browser/render_widget_host_view.h

Index: content/public/browser/render_widget_host_view.h
diff --git a/content/public/browser/render_widget_host_view.h b/content/public/browser/render_widget_host_view.h
index d503fa9db67e32353e9932062ca3125609789823..1b3d70a9a8743d823fbd509e49bc9bb374c90097 100644
--- a/content/public/browser/render_widget_host_view.h
+++ b/content/public/browser/render_widget_host_view.h
@@ -30,6 +30,7 @@ namespace content {
 
 class RenderWidgetHost;
 class RenderWidgetHostViewFrameSubscriber;
+class RenderWidgetHostViewMus;
 
 // RenderWidgetHostView is an interface implemented by an object that acts as
 // the "View" portion of a RenderWidgetHost. The RenderWidgetHost and its
@@ -93,6 +94,9 @@ class CONTENT_EXPORT RenderWidgetHostView {
   // Whether the view is showing.
   virtual bool IsShowing() = 0;
 
+  // Whether this view is managed by mus.
+  virtual RenderWidgetHostViewMus* AsMusView() = 0;
+
   // Indicates if the view is currently occluded (e.g, not visible because it's
   // covered up by other windows), and as a result the view's renderer may be
   // suspended. If Show() is called on a view then its state should be re-set to