Refactor AndroidKeyStore to allow remote key handling.

chrome/android/java/src/org/chromium/chrome/browser/PKCS11AuthenticationManager.java

 // 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.
 
 package org.chromium.chrome.browser;
 
 import android.content.Context;
 
-import java.security.PrivateKey;
 import java.security.cert.X509Certificate;
 
 /**
  * Defines API for managing interaction with SmartCard-based certificate storage using PKCS11.
  */
 public interface PKCS11AuthenticationManager {
 
     /**
      * @return true iff SmartCard-based authentication is available.
      */
     public boolean isPKCS11AuthEnabled();
 
     /**
      * Retrieves the preferred client certificate alias for the given host, port pair, or null if
      * none can be retrieved.
      *
      * @param hostName The host for which to retrieve client certificate.
      * @param port The port to use in conjunction with host to retrieve client certificate.
      */
     public String getClientCertificateAlias(String hostName, int port);
 
     /**
      * Returns the X509Certificate chain for the requested alias, or null if no there is no result.
      */
     public X509Certificate[] getCertificateChain(String alias);
 
     /**
-     * Returns the PrivateKey for the requested alias, or null if no there is no result.
-     */
-    public PrivateKey getPrivateKey(String alias);
-
-    /**
      * Performs necessary initializing for using a PKCS11-based KeysStore. Note that this can
      * perform expensive operations and cannot be done on the UI thread.
      */
     public void initialize(Context context);
 }