ChildProcessSecurityPolicy::CanAccessDataForOrigin workaround to suppress bad kills

content/browser/child_process_security_policy_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/child_process_security_policy_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 799 matching lines @@
   SecurityStateMap::iterator state = security_state_.find(child_id);
   if (state == security_state_.end())
     return false;
   return state->second->HasPermissionsForFile(file, permissions);
 }
 
 bool ChildProcessSecurityPolicyImpl::CanAccessDataForOrigin(int child_id,
                                                             const GURL& gurl) {
   base::AutoLock lock(lock_);
   SecurityStateMap::iterator state = security_state_.find(child_id);
-  if (state == security_state_.end())
-    return false;
+  if (state == security_state_.end()) {
+    // TODO(nick): Returning true instead of false here is a temporary
+    // workaround for https://crbug.com/600441
+    NOTREACHED();

[Charlie Reis, 2016/05/04 19:38:17]

Let's remove the NOTREACHED.  Looks like this is hit in the tests, plus we know
it happens in practice today.  We'll just have to think about how to deal with
it or make it not possible after this CL.

[ncarter (slow), 2016/05/04 19:57:57]

The test that hits it, also fails if we remove the NOTREACHED(). I've edited the
test.

My hope was that the NOTREACHED() might help us track down repro steps.

+    return true;
+  }
   return state->second->CanAccessDataForOrigin(gurl);
 }
 
 void ChildProcessSecurityPolicyImpl::LockToOrigin(int child_id,
                                                   const GURL& gurl) {
   // "gurl" can be currently empty in some cases, such as file://blah.
   DCHECK(SiteInstanceImpl::GetSiteForURL(NULL, gurl) == gurl);
   base::AutoLock lock(lock_);
   SecurityStateMap::iterator state = security_state_.find(child_id);
   DCHECK(state != security_state_.end());
@@ skipping 35 matching lines @@
   base::AutoLock lock(lock_);
 
   SecurityStateMap::iterator state = security_state_.find(child_id);
   if (state == security_state_.end())
     return false;
 
   return state->second->can_send_midi_sysex();
 }
 
 }  // namespace content