Allow MimeHandlerViewGuest be embedded inside OOPIFs

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 fa184a6f5ada6a3ad4f527c5036e4071efb5ea8a..026b1770eeb43c0b9a74380502ed0c8a8bcf5dd9 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.h
+++ b/content/browser/browser_plugin/browser_plugin_guest.h
@@ -63,6 +63,7 @@ class Range;
 namespace content {
 
 class BrowserPluginGuestManager;
+class RenderFrameHostImpl;
 class RenderViewHostImpl;
 class RenderWidgetHost;
 class RenderWidgetHostView;
@@ -279,6 +280,9 @@ class CONTENT_EXPORT BrowserPluginGuest : public GuestHost,
  private:
   class EmbedderVisibilityObserver;
 
+  // The RenderFrameHost embedding/containing the BrowserPlugin.
+  RenderFrameHostImpl* GetEmbedderFrame() const;
+
   void InitInternal(const BrowserPluginHostMsg_Attach_Params& params,
                     WebContentsImpl* owner_web_contents);