Enhance --enable-strict-site-isolation to prevent a site-isolated renderer

content/browser/site_instance.cc

Index: content/browser/site_instance.cc
===================================================================
--- content/browser/site_instance.cc	(revision 110345)
+++ content/browser/site_instance.cc	(working copy)
@@ -4,12 +4,15 @@
 
 #include "content/browser/site_instance.h"
 
+#include "base/command_line.h"
 #include "content/browser/browsing_instance.h"
+#include "content/browser/child_process_security_policy.h"
 #include "content/browser/renderer_host/browser_render_process_host.h"
 #include "content/browser/webui/web_ui_factory.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
+#include "content/public/common/content_switches.h"
 #include "content/public/common/url_constants.h"
 #include "net/base/registry_controlled_domain.h"
 
@@ -85,6 +88,13 @@
 
     // Make sure the process starts at the right max_page_id
     process_->UpdateMaxPageID(max_page_id_);
+
+    const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+    if (command_line.HasSwitch(switches::kEnableStrictSiteIsolation)) {
+      ChildProcessSecurityPolicy* policy =
+          ChildProcessSecurityPolicy::GetInstance();
+      policy->LockToOrigin(process_->id(), site_);

[Charlie Reis, 2011/11/22 19:06:59]

Hmm, a SiteInstance's site_ isn't always set by the time GetProcess() is called
(which helps deal with redirects).  For example, if you open a bookmark in a new
tab, GetProcess gets called before SetSite.  If you open a bookmark in the
current tab, SetSite gets called before GetProcess.

I think we might have to move this to a helper and call it from both GetProcess
and SetSite, whichever comes first (e.g., checking if has_site here, and if
process_ below).

+    }
   }
   DCHECK(process_);