Making OAuth2TokenService multi-login aware, updating callers, minor fixes

sync/android/java/src/org/chromium/sync/signin/AccountManagerHelper.java

 // 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.
 
 package org.chromium.sync.signin;
 
 
 import com.google.common.annotations.VisibleForTesting;
 
 import android.accounts.Account;
@@ skipping 118 matching lines @@
         Account[] accounts = mAccountManager.getAccountsByType(GOOGLE_ACCOUNT_TYPE);
         for (Account account : accounts) {
             if (account.name.equals(accountName)) {
                 return account;
             }
         }
         return null;
     }
 
     /**
+     * Returns whether the accounts exists.
+     */
+    public boolean hasAccountForName(String accountName) {
+        return getAccountFromName(accountName) != null;
+    }
+
+    /**
      * @return Whether or not there is an account authenticator for Google accounts.
      */
     public boolean hasGoogleAccountAuthenticator() {
         AuthenticatorDescription[] descs = mAccountManager.getAuthenticatorTypes();
         for (AuthenticatorDescription desc : descs) {
             if (GOOGLE_ACCOUNT_TYPE.equals(desc.type)) return true;
         }
         return false;
     }
 
@@ skipping 187 matching lines @@
             null, account, authTokenType, callback, numTries, errorEncountered, null);
     }
 
     /**
      * Removes an auth token from the AccountManager's cache.
      */
     public void invalidateAuthToken(String authToken) {
         mAccountManager.invalidateAuthToken(GOOGLE_ACCOUNT_TYPE, authToken);
     }
 }