Disallow UI/IO thread blocking on any other thread.

content/browser/browser_main_loop.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_main_loop.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 409 matching lines @@
 #endif
 
   BrowserThreadsStarted();
 
   if (parts_.get())
     parts_->PreMainMessageLoopRun();
 
   // If the UI thread blocks, the whole UI is unresponsive.
   // Do not allow disk IO from the UI thread.
   base::ThreadRestrictions::SetIOAllowed(false);
+  base::ThreadRestrictions::DisallowWaiting();
 
   // When running the GPU thread in-process, avoid optimistically starting it
   // since creating the GPU thread races against creation of the one-and-only
   // ChildProcess instance which is created by the renderer thread.
   if (!parsed_command_line_.HasSwitch(switches::kSingleProcess) &&
       !parsed_command_line_.HasSwitch(switches::kInProcessGPU)) {
     BrowserThread::PostDelayedTask(
         BrowserThread::IO, FROM_HERE, base::Bind(
             base::IgnoreResult(&GpuProcessHost::Get),
             GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
@@ skipping 197 matching lines @@
     MessageLoopForUI::current()->PostTask(FROM_HERE, *parameters_.ui_task);
 
 #if defined(OS_MACOSX)
   MessageLoopForUI::current()->Run();
 #else
   MessageLoopForUI::current()->RunWithDispatcher(NULL);
 #endif
 }
 
 }  // namespace content