chromeos: Simplify D-Bus proxy provider (but not tests).

chrome/browser/chromeos/dbus/chrome_proxy_resolution_service_provider_delegate.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_DBUS_CHROME_PROXY_RESOLUTION_SERVICE_PROVIDER_DELEGATE_H_
 #define CHROME_BROWSER_CHROMEOS_DBUS_CHROME_PROXY_RESOLUTION_SERVICE_PROVIDER_DELEGATE_H_
 
 #include "base/macros.h"
 #include "chromeos/dbus/services/proxy_resolution_service_provider.h"
 
 namespace chromeos {
 
 // Chrome's implementation of ProxyResolutionServiceProvider::Delegate.
 class ChromeProxyResolutionServiceProviderDelegate
     : public ProxyResolutionServiceProvider::Delegate {
  public:
   ChromeProxyResolutionServiceProviderDelegate();
   ~ChromeProxyResolutionServiceProviderDelegate() override;
 
   // ProxyResolutionServiceProvider::Delegate:
   scoped_refptr<net::URLRequestContextGetter> GetRequestContext() override;
-  int ResolveProxy(net::ProxyService* proxy_service,
-                   const GURL& url,
-                   net::ProxyInfo* results,
-                   const net::CompletionCallback& callback) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ChromeProxyResolutionServiceProviderDelegate);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_DBUS_CHROME_PROXY_RESOLUTION_SERVICE_PROVIDER_DELEGATE_H_