Do not block document.written scripts in page reloads

third_party/WebKit/Source/core/loader/FrameFetchContext.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 69 matching lines @@
 bool shouldDisallowFetchForMainFrameScript(const ResourceRequest& request, FetchRequest::DeferOption defer, const Document& document)
 {
     // Only scripts inserted via document.write are candidates for having their
     // fetch disallowed.
     if (!document.isInDocumentWrite())
         return false;
 
     if (!document.settings())
         return false;
 
+    if (document.frame())

[shivanisha, 2016/04/13 16:52:16]

Changing this to if (!document.frame())

+        return false;
+
+    // Do not block scripts if it is a page reload. This is to enable pages to
+    // recover if blocking of a script is leading to a page break and the user
+    // reloads the page.
+    const FrameLoadType loadType = document.frame()->loader().loadType();
+    const bool isReload = (loadType == FrameLoadTypeReload || loadType == FrameLoadTypeReloadBypassingCache);
+    if (isReload)
+        return false;
+

[shivanisha, 2016/04/13 15:56:58]

There is also a FrameLoadType value: FrameLoadTypeSame which implies user loads
same URL again (but not reload button). I think its fine to not consider that
case. WDYT?

     const bool isSlowConnection = networkStateNotifier().connectionType() == WebConnectionTypeCellular2G;
     const bool disallowFetch = document.settings()->disallowFetchForDocWrittenScriptsInMainFrame() || (document.settings()->disallowFetchForDocWrittenScriptsInMainFrameOnSlowConnections() && isSlowConnection);
     if (!disallowFetch)
         return false;
 
     // Only block synchronously loaded (parser blocking) scripts.
     if (defer != FetchRequest::NoDefer)
         return false;
 
     // Avoid blocking same origin scripts, as they may be used to render main
@@ skipping 693 matching lines @@
 }
 
 DEFINE_TRACE(FrameFetchContext)
 {
     visitor->trace(m_document);
     visitor->trace(m_documentLoader);
     FetchContext::trace(visitor);
 }
 
 } // namespace blink