Use GoogleAuthUtil's getToken instead of AccountManager

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

Index: sync/android/java/src/org/chromium/sync/signin/SystemAccountManagerDelegate.java
diff --git a/sync/android/java/src/org/chromium/sync/signin/SystemAccountManagerDelegate.java b/sync/android/java/src/org/chromium/sync/signin/SystemAccountManagerDelegate.java
index 75777dd85acde0e749bc10292bebb132bcc49aca..15dfbe1a842ff1b3d9639674d702d13715112938 100644
--- a/sync/android/java/src/org/chromium/sync/signin/SystemAccountManagerDelegate.java
+++ b/sync/android/java/src/org/chromium/sync/signin/SystemAccountManagerDelegate.java
@@ -13,11 +13,13 @@ import android.accounts.AuthenticatorException;
 import android.accounts.OperationCanceledException;
 import android.content.Context;
 import android.os.AsyncTask;
-import android.os.Bundle;
-import android.os.Handler;
 import android.os.StrictMode;
 import android.os.SystemClock;
 
+import com.google.android.gms.auth.GoogleAuthException;
+import com.google.android.gms.auth.GoogleAuthUtil;
+import com.google.android.gms.auth.UserRecoverableAuthException;
+
 import org.chromium.base.Callback;
 import org.chromium.base.Log;
 import org.chromium.base.ThreadUtils;
@@ -70,10 +72,18 @@ public class SystemAccountManagerDelegate implements AccountManagerDelegate {
     }
 
     @Override
-    public AccountManagerFuture<Bundle> getAuthToken(Account account, String authTokenType,
-            boolean notifyAuthFailure, AccountManagerCallback<Bundle> callback, Handler handler) {
-        return mAccountManager.getAuthToken(account, authTokenType, null, notifyAuthFailure,
-                callback, handler);
+    public String getAuthToken(Account account, String authTokenScope) throws AuthException {
+        assert !ThreadUtils.runningOnUiThread();
+        assert AccountManagerHelper.GOOGLE_ACCOUNT_TYPE.equals(account.type);
+        try {
+            return GoogleAuthUtil.getToken(mApplicationContext, account.name, authTokenScope);
+        } catch (UserRecoverableAuthException ex) {
+            throw new AuthException(false /* isTransientError */, ex.getIntent(), ex);
+        } catch (GoogleAuthException ex) {
+            throw new AuthException(false /* isTransientError */, null, ex);
+        } catch (IOException ex) {
+            throw new AuthException(true /* isTransientError */, null, ex);
+        }
     }
 
     @Override