Force MimeHandlerView to always use BrowserPlugin

chrome/browser/renderer_context_menu/render_view_context_menu.cc

Index: chrome/browser/renderer_context_menu/render_view_context_menu.cc
diff --git a/chrome/browser/renderer_context_menu/render_view_context_menu.cc b/chrome/browser/renderer_context_menu/render_view_context_menu.cc
index 210adc6d75d706936ca9186a699bc107e60d67e6..912a74c6ecfc0000bede946a126eb5c35d491882 100644
--- a/chrome/browser/renderer_context_menu/render_view_context_menu.cc
+++ b/chrome/browser/renderer_context_menu/render_view_context_menu.cc
@@ -74,6 +74,7 @@
 #include "components/autofill/core/common/password_generation_util.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 #include "components/google/core/browser/google_util.h"
+#include "components/guest_view/browser/guest_view_base.h"
 #include "components/metrics/proto/omnibox_input_type.pb.h"
 #include "components/omnibox/browser/autocomplete_classifier.h"
 #include "components/omnibox/browser/autocomplete_match.h"
@@ -108,6 +109,7 @@
 #include "content/public/common/url_utils.h"
 #include "extensions/browser/extension_host.h"
 #include "extensions/browser/extension_system.h"
+#include "extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.h"
 #include "extensions/browser/guest_view/web_view/web_view_guest.h"
 #include "extensions/browser/view_type_utils.h"
 #include "extensions/common/extension.h"
@@ -500,7 +502,13 @@ gfx::Vector2d RenderViewContextMenu::GetOffset(
 #if defined(ENABLE_EXTENSIONS)
   // When --use-cross-process-frames-for-guests is enabled, the position is
   // transformed in the browser process hittesting code.
-  if (!content::BrowserPluginGuestMode::UseCrossProcessFramesForGuests()) {
+  // TODO(ekaramad): For now, MimeHandlerView is based on BrowserPlugin even
+  // when guests use OOPIF. Remove the check below when MimeHandlerView is also
+  // based on OOPIF (https://crbug.com/563285).
+  WebContents* web_contents =
+      WebContents::FromRenderFrameHost(render_frame_host);
+  if (!content::BrowserPluginGuestMode::UseCrossProcessFramesForGuests() ||
+      guest_view::GuestViewBase::IsForMimeHandlerViewGuest(web_contents)) {
     WebContents* web_contents =
         WebContents::FromRenderFrameHost(render_frame_host);
     WebContents* top_level_web_contents =