Tweaks to new BrowserThreadImpl/BrowserMainLoop logic.

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 338 matching lines @@
 }
 
 // static
 void BrowserThreadImpl::ResetGlobalsForTesting(BrowserThread::ID identifier) {
   BrowserThreadGlobals& globals = g_globals.Get();
 
   base::AutoLock lock(globals.lock);
   DCHECK_EQ(globals.states[identifier], BrowserThreadState::SHUTDOWN);
   globals.states[identifier] = BrowserThreadState::UNINITIALIZED;
   globals.task_runners[identifier] = nullptr;
-  SetIOThreadDelegate(nullptr);
+  if (identifier == BrowserThread::IO)
+    SetIOThreadDelegate(nullptr);

[gab, 2017/01/10 15:48:28]

This call only needs to happen once for the IO thread.

 }
 
 BrowserThreadImpl::~BrowserThreadImpl() {
   // All Thread subclasses must call Stop() in the destructor. This is
   // doubly important here as various bits of code check they are on
   // the right BrowserThread.
   Stop();
 
   BrowserThreadGlobals& globals = g_globals.Get();
   base::AutoLock lock(globals.lock);
@@ skipping 325 matching lines @@
   BrowserThreadDelegateAtomicPtr old_delegate =
       base::subtle::NoBarrier_AtomicExchange(
           &globals.io_thread_delegate,
           reinterpret_cast<BrowserThreadDelegateAtomicPtr>(delegate));
 
   // This catches registration when previously registered.
   DCHECK(!delegate || !old_delegate);
 }
 
 }  // namespace content