Navigation transitions: Place transition page in same process as destination page.

content/browser/site_instance_impl.cc

 // Copyright (c) 2012 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/site_instance_impl.h"
 
 #include "base/command_line.h"
 #include "content/browser/browsing_instance.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/frame_host/debug_urls.h"
@@ skipping 243 matching lines @@
   // Some special URLs will match the site instance of any other URL. This is
   // done before checking both of them for validity, since we want these URLs
   // to have the same site instance as even an invalid one.
   if (IsRendererDebugURL(url1) || IsRendererDebugURL(url2))
     return true;
 
   // If either URL is invalid, they aren't part of the same site.
   if (!url1.is_valid() || !url2.is_valid())
     return false;
 
+  // If either url is just a blank page, we treat them as part of the same site.

[Charlie Reis, 2014/07/25 17:31:22]

Ah, we don't actually want this for navigating from about:blank to a normal URL,
since it's possible for one website to inject content into an about:blank popup
(via JavaScript) and then navigate it elsewhere.  It's only ok when going from a
normal URL to about:blank.

I still think this change makes sense for src -> dest, so perhaps we should
change the names of url1 and url2 to src_url and dest_url (here and in the .h
file), and add a mention of this behavior in the declaration comment in
site_instance.h.

[shatch, 2014/07/25 20:57:05]

Done.

+  GURL blank_page = GURL(url::kAboutBlankURL);
+  if (url1 == blank_page || url2 == blank_page)
+    return true;
+
   // If the schemes differ, they aren't part of the same site.
   if (url1.scheme() != url2.scheme())
     return false;
 
   return net::registry_controlled_domains::SameDomainOrHost(
       url1,
       url2,
       net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES);
 }
 
@@ skipping 58 matching lines @@
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kEnableStrictSiteIsolation) ||
       command_line.HasSwitch(switches::kSitePerProcess)) {
     ChildProcessSecurityPolicyImpl* policy =
         ChildProcessSecurityPolicyImpl::GetInstance();
     policy->LockToOrigin(process_->GetID(), site_);
   }
 }
 
 }  // namespace content