Why this CL triggers an OilPan crash.

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/memory/ptr_util.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 257 matching lines @@
 }
 
 bool SiteInstanceImpl::HasSite() const {
   return has_site_;
 }
 
 bool SiteInstanceImpl::HasRelatedSiteInstance(const GURL& url) {
   return browsing_instance_->HasSiteInstance(url);
 }
 
+int SiteInstanceImpl::GetBrowsingInstanceId() const {
+  return browsing_instance_->browsing_instance_id();
+}
+
 scoped_refptr<SiteInstance> SiteInstanceImpl::GetRelatedSiteInstance(
     const GURL& url) {
   return browsing_instance_->GetSiteInstanceForURL(url);
 }
 
 bool SiteInstanceImpl::IsRelatedSiteInstance(const SiteInstance* instance) {
   return browsing_instance_.get() == static_cast<const SiteInstanceImpl*>(
                                          instance)->browsing_instance_.get();
 }
 
@@ skipping 235 matching lines @@
             browsing_instance_->browser_context(), site_))
       return;
 
     ChildProcessSecurityPolicyImpl* policy =
         ChildProcessSecurityPolicyImpl::GetInstance();
     policy->LockToOrigin(process_->GetID(), site_);
   }
 }
 
 }  // namespace content