Let pyauto create an attached webdriver instance to manipulate web pages.

chrome/browser/automation/automation_provider.cc

 // Copyright (c) 2011 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/automation/automation_provider.h"
 
 #include <set>
 
 #include "base/callback.h"
 #include "base/debug/trace_event.h"
@@ skipping 138 matching lines @@
     if (effective_channel_id.length() <= 0)
       return false;
 
     reinitialize_on_channel_error_ = true;
   }
 
   if (!automation_resource_message_filter_.get()) {
     automation_resource_message_filter_ = new AutomationResourceMessageFilter;
   }
 
+  base::ThreadRestrictions::ScopedAllowIO allow_io;

[Paweł Hajdan Jr., 2011/08/02 23:31:24]

My NAK on this still holds.

[kkania, 2011/08/03 17:38:00]

Fixing this problem will require some significant changes, which is why I split
it into a separate CL. I don't see a reason to block this CL waiting for that to
occur. This CL does not introduce the core problem here, although it reuses some
bad code. What do you think?

Added TODO to remove this when underlying issue is fixed.

[Paweł Hajdan Jr., 2011/08/03 19:09:16]

Then please do those changes. What is so hard about it?

   channel_.reset(new IPC::ChannelProxy(
       effective_channel_id,
       GetChannelMode(use_named_interface),
       this,
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO)));
   channel_->AddFilter(automation_resource_message_filter_);
 
 #if defined(OS_CHROMEOS)
   // Wait for the network manager to initialize.
   // The observer will delete itself when done.
@@ skipping 245 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(InvokeTaskLaterTask);
 };
 
 void AutomationProvider::HandleUnused(const IPC::Message& message, int handle) {
   if (window_tracker_->ContainsHandle(handle)) {
     window_tracker_->Remove(window_tracker_->GetResource(handle));
   }
 }
 
 bool AutomationProvider::ReinitializeChannel() {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
-
   // Make sure any old channels are cleaned up before starting up a new one.
   channel_.reset();
   return InitializeChannel(channel_id_);
 }
 
 void AutomationProvider::OnChannelError() {
   if (reinitialize_on_channel_error_) {
     VLOG(1) << "AutomationProxy disconnected, resetting AutomationProvider.";
     if (ReinitializeChannel())
       return;
@@ skipping 524 matching lines @@
     }
   }
 }
 
 void AutomationProvider::SaveAsAsync(int tab_handle) {
   NavigationController* tab = NULL;
   TabContents* tab_contents = GetTabContentsForHandle(tab_handle, &tab);
   if (tab_contents)
     tab_contents->OnSavePage();
 }