Make HistoryDBTask not refcounted, and ensure it's destroyed on its origin thread.

chrome/browser/ui/webui/signin/inline_login_handler_impl.cc

 // Copyright 2013 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/ui/webui/signin/inline_login_handler_impl.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 20 matching lines @@
 #include "content/public/browser/storage_partition.h"
 #include "content/public/browser/web_ui.h"
 #include "google_apis/gaia/gaia_auth_fetcher.h"
 #include "google_apis/gaia/gaia_auth_util.h"
 #include "google_apis/gaia/gaia_constants.h"
 #include "google_apis/gaia/gaia_urls.h"
 #include "net/base/url_util.h"
 
 namespace {
 
-class InlineSigninHelper : public SigninOAuthHelper,
-                           public SigninOAuthHelper::Consumer {
+class InlineSigninHelper : public SigninOAuthHelper::Consumer {
  public:
   InlineSigninHelper(
       base::WeakPtr<InlineLoginHandlerImpl> handler,
       net::URLRequestContextGetter* getter,
       Profile* profile,
       const GURL& current_url,
       const std::string& email,
       const std::string& password,
       const std::string& session_index,
       const std::string& signin_scoped_device_id,
       bool choose_what_to_sync);
 
  private:
   // Overriden from SigninOAuthHelper::Consumer.
   virtual void OnSigninOAuthInformationAvailable(
       const std::string& email,
       const std::string& display_email,
       const std::string& refresh_token) OVERRIDE;
   virtual void OnSigninOAuthInformationFailure(
       const GoogleServiceAuthError& error) OVERRIDE;
 
+  SigninOAuthHelper signin_oauth_helper_;
   base::WeakPtr<InlineLoginHandlerImpl> handler_;
   Profile* profile_;
   GURL current_url_;
   std::string email_;
   std::string password_;
   std::string session_index_;
   bool choose_what_to_sync_;
 
   DISALLOW_COPY_AND_ASSIGN(InlineSigninHelper);
 };
 
 InlineSigninHelper::InlineSigninHelper(
     base::WeakPtr<InlineLoginHandlerImpl> handler,
     net::URLRequestContextGetter* getter,
     Profile* profile,
     const GURL& current_url,
     const std::string& email,
     const std::string& password,
     const std::string& session_index,
     const std::string& signin_scoped_device_id,
     bool choose_what_to_sync)
-    : SigninOAuthHelper(getter, session_index, signin_scoped_device_id, this),
+    : signin_oauth_helper_(getter, session_index, signin_scoped_device_id,
+                           this),
       handler_(handler),
       profile_(profile),
       current_url_(current_url),
       email_(email),
       password_(password),
       choose_what_to_sync_(choose_what_to_sync) {
   DCHECK(profile_);
   DCHECK(!email_.empty());
 }
 
@@ skipping 291 matching lines @@
       }
     }
 
     if (show_account_management) {
       browser->window()->ShowAvatarBubbleFromAvatarButton(
             BrowserWindow::AVATAR_BUBBLE_MODE_ACCOUNT_MANAGEMENT,
             signin::ManageAccountsParams());
     }
   }
 }