Force MimeHandlerView to always use BrowserPlugin

content/browser/browser_plugin/browser_plugin_guest.h

Index: content/browser/browser_plugin/browser_plugin_guest.h
diff --git a/content/browser/browser_plugin/browser_plugin_guest.h b/content/browser/browser_plugin/browser_plugin_guest.h
index ccfb0b990d3b2ee748ae053495a6f266f796ef71..e0e956a1569bcba7f99334e1533c887aa95ccb61 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.h
+++ b/content/browser/browser_plugin/browser_plugin_guest.h
@@ -156,6 +156,7 @@ class CONTENT_EXPORT BrowserPluginGuest : public GuestHost,
   // Returns the embedder's RenderWidgetHostView if it is available.
   // Returns nullptr otherwise.
   RenderWidgetHostView* GetOwnerRenderWidgetHostView();
+  RenderWidgetHostView* GetTopLevelRenderWidgetHostView();
 
   bool focused() const { return focused_; }
   bool visible() const { return guest_visible_; }
@@ -253,6 +254,11 @@ class CONTENT_EXPORT BrowserPluginGuest : public GuestHost,
 
   void ResendEventToEmbedder(const blink::WebInputEvent& event);
 
+  // TODO(ekaramad): This is used in forcing MimeHandlerView use BrowserPlugin
+  // even when --use-cross-process-frames-for-guests is used. Remove this once
+  // MimeHandlerView uses OOPIF (https://crbug.com/563285).
+  bool IsMimeHandlerViewGuest() const;
+
  protected:
 
   // BrowserPluginGuest is a WebContentsObserver of |web_contents| and