Disable ProfileKeyedServices on import process by default.

chrome/browser/webdata/web_data_service.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/webdata/web_data_service.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
@@ skipping 69 matching lines @@
 WebDataService::WebDataService()
     : is_running_(false),
       db_(NULL),
       request_manager_(new WebDataRequestManager()),
       app_locale_(AutofillCountry::ApplicationLocale()),
       autocomplete_syncable_service_(NULL),
       autofill_profile_syncable_service_(NULL),
       failed_init_(false),
       should_commit_(false),
       main_loop_(MessageLoop::current()) {
+  // WebDataService takes ownership of a non-sharable resource (Web Data DB
+  // file) and so should never be launched on the import process, as it can
+  // grab the resource before the main browser process does.
+  CHECK(!ProfileManager::IsImportProcess(*CommandLine::ForCurrentProcess()));

[gab, 2013/03/07 15:46:57]

FWIW, we (me and macourteau) were hitting the DCHECK below when using
import_search_engine in master_preferences (http://crbug.com/180306); we are
investigating the root cause, but making this a CHECK will cause the import
process to crash for everyone using that preference...

+
   // WebDataService requires DB thread if instantiated.
   // Set WebDataServiceFactory::GetInstance()->SetTestingFactory(&profile, NULL)
   // if you do not want to instantiate WebDataService in your test.
-  DCHECK(!ProfileManager::IsImportProcess(*CommandLine::ForCurrentProcess()));
   DCHECK(BrowserThread::IsWellKnownThread(BrowserThread::DB));
 }
 
 // static
 void WebDataService::NotifyOfMultipleAutofillChanges(
     WebDataService* web_data_service) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
 
   if (!web_data_service)
     return;
@@ skipping 844 matching lines @@
 
 void WebDataService::DestroyAutofillCreditCardResult(
       const WDTypedResult* result) {
   DCHECK(result->GetType() == AUTOFILL_CREDITCARDS_RESULT);
   const WDResult<std::vector<CreditCard*> >* r =
       static_cast<const WDResult<std::vector<CreditCard*> >*>(result);
 
   std::vector<CreditCard*> credit_cards = r->GetValue();
   STLDeleteElements(&credit_cards);
 }