Don't abort the PDF stream if a navigation is intiated within the same page.

extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.cc

Index: extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.cc
diff --git a/extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.cc b/extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.cc
index a4657c9b0af568f40903e7bee1c4f2f108fb003c..aa2a7f87c3fb39f89c36ced3af0f55ae848d7e0f 100644
--- a/extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.cc
+++ b/extensions/browser/guest_view/mime_handler_view/mime_handler_stream_manager.cc
@@ -223,7 +223,7 @@ void MimeHandlerStreamManager::EmbedderObserver::
 void MimeHandlerStreamManager::EmbedderObserver::DidStartNavigation(
     content::NavigationHandle* navigation_handle) {
   // If the top level frame is navigating away, clean up the stream.
-  if (navigation_handle->IsInMainFrame())
+  if (navigation_handle->IsInMainFrame() && !navigation_handle->IsSamePage())
     AbortStream();
 }