The base unittests were succeeding for the isolated...

base/observer_list_threadsafe.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef BASE_OBSERVER_LIST_THREADSAFE_H_
 #define BASE_OBSERVER_LIST_THREADSAFE_H_
 
 #include <vector>
 #include <algorithm>
 
@@ skipping 46 matching lines @@
     typename ObserversListMap::const_iterator it;
     for (it = observer_lists_.begin(); it != observer_lists_.end(); ++it)
       delete (*it).second;
     observer_lists_.clear();
   }
 
   // Add an observer to the list.
   void AddObserver(ObserverType* obs) {
     ObserverList<ObserverType>* list = NULL;
     MessageLoop* loop = MessageLoop::current();
+    if (!loop)
+      return;  // Some unittests may access this without a message loop.
     {
       AutoLock lock(list_lock_);
       if (observer_lists_.find(loop) == observer_lists_.end())
         observer_lists_[loop] = new ObserverList<ObserverType>();
       list = observer_lists_[loop];
     }
     list->AddObserver(obs);
   }
 
   // Remove an observer from the list.
@@ skipping 108 matching lines @@
   typedef std::map<MessageLoop*, ObserverList<ObserverType>*> ObserversListMap;
 
   // These are marked mutable to facilitate having NotifyAll be const.
   Lock list_lock_;  // Protects the observer_lists_.
   ObserversListMap observer_lists_;
 
   DISALLOW_EVIL_CONSTRUCTORS(ObserverListThreadSafe);
 };
 
 #endif  // BASE_OBSERVER_LIST_THREADSAFE_H_