Force MimeHandlerView to always use BrowserPlugin

content/public/common/browser_plugin_guest_mode.cc

Index: content/public/common/browser_plugin_guest_mode.cc
diff --git a/content/public/common/browser_plugin_guest_mode.cc b/content/public/common/browser_plugin_guest_mode.cc
index 7c3986a3f2f0dccccd686c1fdc77c40e907051c0..5ae640590bf9912d3987d69fdbbef83f405653f4 100644
--- a/content/public/common/browser_plugin_guest_mode.cc
+++ b/content/public/common/browser_plugin_guest_mode.cc
@@ -5,6 +5,9 @@
 #include "content/public/common/browser_plugin_guest_mode.h"
 
 #include "base/command_line.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_plugin_guest_manager.h"
+#include "content/public/browser/web_contents.h"
 #include "content/public/common/content_switches.h"
 
 namespace content {
@@ -15,4 +18,12 @@ bool BrowserPluginGuestMode::UseCrossProcessFramesForGuests() {
       switches::kUseCrossProcessFramesForGuests);
 }
 
+bool BrowserPluginGuestMode::UseCrossProcessFramesForWebContents(
+    content::WebContents* web_contents) {
+  return UseCrossProcessFramesForGuests() &&
+         !web_contents->GetBrowserContext()
+              ->GetGuestManager()
+              ->IsForMimeHandlerViewGuest(web_contents);
+}
+
 }  // namespace content