Disallow UI/IO thread blocking on any other thread.

chrome/browser/io_thread.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 "chrome/browser/io_thread.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/debug/leak_tracker.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/string_number_conversions.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "base/threading/thread.h"
-#include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_event_router_forwarder.h"
 #include "chrome/browser/net/chrome_net_log.h"
 #include "chrome/browser/net/chrome_network_delegate.h"
 #include "chrome/browser/net/chrome_url_request_context.h"
 #include "chrome/browser/net/connect_interceptor.h"
 #include "chrome/browser/net/http_pipelining_compatibility_client.h"
 #include "chrome/browser/net/pref_proxy_config_tracker.h"
 #include "chrome/browser/net/proxy_service_factory.h"
@@ skipping 336 matching lines @@
 
 net::URLRequestContextGetter* IOThread::system_url_request_context_getter() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (!system_url_request_context_getter_) {
     InitSystemRequestContext();
   }
   return system_url_request_context_getter_;
 }
 
 void IOThread::Init() {
-  // Though this thread is called the "IO" thread, it actually just routes
-  // messages around; it shouldn't be allowed to perform any blocking disk I/O.
-  base::ThreadRestrictions::SetIOAllowed(false);
-
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
 #if defined(USE_NSS)
   net::SetMessageLoopForNSSHttpIO();
 #endif  // defined(USE_NSS)
 
   DCHECK(!globals_);
   globals_ = new Globals;
 
   // Add an observer that will emit network change events to the ChromeNetLog.
@@ skipping 222 matching lines @@
       new net::HttpNetworkLayer(
           new net::HttpNetworkSession(system_params)));
   globals_->system_ftp_transaction_factory.reset(
       new net::FtpNetworkLayer(globals_->host_resolver.get()));
   globals_->system_request_context =
       ConstructSystemRequestContext(globals_, net_log_);
 
   sdch_manager_->set_sdch_fetcher(
       new SdchDictionaryFetcher(system_url_request_context_getter_.get()));
 }