Allow "cross-origin" navigations from about:blank in AreURLsInPageNavigation

content/browser/frame_host/navigation_controller_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/frame_host/navigation_controller_impl.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 105 matching lines @@
 // The one thing we do know is that cross-origin navigations will *never* be
 // in-page. Therefore, trust the renderer if the URLs are on the same origin,
 // and assume the renderer is malicious if a cross-origin navigation claims to
 // be in-page.
 bool AreURLsInPageNavigation(const GURL& existing_url,
                              const GURL& new_url,
                              bool renderer_says_in_page,
                              RenderFrameHost* rfh) {
   WebPreferences prefs = rfh->GetRenderViewHost()->GetWebkitPreferences();
   bool is_same_origin = existing_url.is_empty() ||
+                        existing_url == GURL(url::kAboutBlankURL) ||

[nasko, 2014/07/09 07:11:17]

Shouldn't this only apply if there is no session history? It looks like any
navigation to about:blank anywhere in the history will allow this true.

                         existing_url.GetOrigin() == new_url.GetOrigin() ||
                         !prefs.web_security_enabled;
   if (!is_same_origin && renderer_says_in_page)
       rfh->GetProcess()->ReceivedBadMessage();
   return is_same_origin && renderer_says_in_page;
 }
 
 // Determines whether or not we should be carrying over a user agent override
 // between two NavigationEntries.
 bool ShouldKeepOverride(const NavigationEntry* last_entry) {
@@ skipping 1639 matching lines @@
     }
   }
 }
 
 void NavigationControllerImpl::SetGetTimestampCallbackForTest(
     const base::Callback<base::Time()>& get_timestamp_callback) {
   get_timestamp_callback_ = get_timestamp_callback;
 }
 
 }  // namespace content