Fix context menu positioning in MimeHandlerViewGuest.

chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc

Index: chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc
diff --git a/chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc b/chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc
index 0423d541a5f612ea98b22f53b2078b5085c79d26..f4c32e165bea59836611229bdadf7375434f2dbb 100644
--- a/chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc
+++ b/chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc
@@ -5,8 +5,10 @@
 #include "chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.h"
 
 #include "chrome/browser/chrome_page_zoom.h"
+#include "chrome/browser/renderer_context_menu/render_view_context_menu.h"
 #include "chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h"
 #include "components/pdf/browser/pdf_web_contents_helper.h"
+#include "components/renderer_context_menu/context_menu_delegate.h"
 #include "extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.h"
 
 #if defined(ENABLE_PRINTING)
@@ -53,4 +55,17 @@ void ChromeMimeHandlerViewGuestDelegate::ChangeZoom(bool zoom_in) {
       zoom_in ? content::PAGE_ZOOM_IN : content::PAGE_ZOOM_OUT);
 }
 
+bool ChromeMimeHandlerViewGuestDelegate::HandleContextMenu(
+    content::WebContents* web_contents,
+    const content::ContextMenuParams& params) {
+  ContextMenuDelegate* menu_delegate =
+      ContextMenuDelegate::FromWebContents(web_contents);
+  DCHECK(menu_delegate);
+
+  scoped_ptr<RenderViewContextMenu> menu =
+      menu_delegate->BuildMenu(web_contents, params);
+  menu_delegate->ShowMenu(menu.Pass());
+  return true;
+}
+
 }  // namespace extensions