Force MimeHandlerView to always use BrowserPlugin

components/guest_view/browser/guest_view_base.h

Index: components/guest_view/browser/guest_view_base.h
diff --git a/components/guest_view/browser/guest_view_base.h b/components/guest_view/browser/guest_view_base.h
index 320a5e4d50b269831aeb861b657a7c3d3f4646df..f847153b2f914ad8371572aa93188d8b240d013c 100644
--- a/components/guest_view/browser/guest_view_base.h
+++ b/components/guest_view/browser/guest_view_base.h
@@ -84,6 +84,11 @@ class GuestViewBase : public content::BrowserPluginGuestDelegate,
 
   static bool IsGuest(content::WebContents* web_contents);
 
+  // TODO(ekaramad): This is used in forcing MimeHandlerView always use a
+  // BrowserPlugin rather than <iframe> (OOPIF). Remove this when we fix
+  // https://crbug.com/563285.
+  static bool IsForMimeHandlerViewGuest(content::WebContents* web_contents);
+
   // Returns the name of the derived type of this GuestView.
   virtual const char* GetViewType() const = 0;