Ensure tests have an active task runner

content/browser/browser_thread_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/browser_thread_impl.h"
 
 #include <string>
 
 #include "base/atomicops.h"
 #include "base/bind.h"
@@ skipping 290 matching lines @@
 }
 
 // static
 bool BrowserThreadImpl::PostTaskHelper(
     BrowserThread::ID identifier,
     const tracked_objects::Location& from_here,
     const base::Closure& task,
     base::TimeDelta delay,
     bool nestable) {
   DCHECK(identifier >= 0 && identifier < ID_COUNT);
+  // We don't want to create a pool if none exists.
+  if (g_globals == NULL)
+    return false;
   // Optimization: to avoid unnecessary locks, we listed the ID enumeration in
   // order of lifetime.  So no need to lock if we know that the target thread
   // outlives current thread.
   // Note: since the array is so small, ok to loop instead of creating a map,
   // which would require a lock because std::map isn't thread safe, defeating
   // the whole purpose of this optimization.
   BrowserThread::ID current_thread = ID_COUNT;
   bool target_thread_outlives_current =
       GetCurrentThreadIdentifier(&current_thread) &&
       current_thread >= identifier;
@@ skipping 219 matching lines @@
   AtomicWord* storage = reinterpret_cast<AtomicWord*>(
       &globals.thread_delegates[identifier]);
   AtomicWord old_pointer = base::subtle::NoBarrier_AtomicExchange(
       storage, reinterpret_cast<AtomicWord>(delegate));
 
   // This catches registration when previously registered.
   DCHECK(!delegate || !old_pointer);
 }
 
 }  // namespace content