Force MimeHandlerView to always use BrowserPlugin

content/public/common/browser_plugin_guest_mode.h

Index: content/public/common/browser_plugin_guest_mode.h
diff --git a/content/public/common/browser_plugin_guest_mode.h b/content/public/common/browser_plugin_guest_mode.h
index c77a1e8e53744b140e6e7a6f381c4d3849888044..fd84672836fd42da897db4a961546653b7f2a6f0 100644
--- a/content/public/common/browser_plugin_guest_mode.h
+++ b/content/public/common/browser_plugin_guest_mode.h
@@ -10,12 +10,20 @@
 
 namespace content {
 
+class WebContents;
+
 class CONTENT_EXPORT BrowserPluginGuestMode {
  public:
   // Returns true if inner WebContents should be implemented in terms of cross-
   // process iframes.
   static bool UseCrossProcessFramesForGuests();
 
+  // TODO(ekaramad): Remove the following method once MimeHandlerViewGuest uses
+  // OOPIF (https://crbug.com/563285).
+  // Returns true if the given |web_contents| is implemented in terms of
+  // cross-process iframes.
+  static bool UseCrossProcessFramesForWebContents(WebContents* web_contents);
+
  private:
   BrowserPluginGuestMode();  // Not instantiable