Errore compilazione GoogleApiClient cannot be resolved to a type

salve io vorrei usare google drive ma non riesco a far compilare

codice:

---

package com.google.android.gms.drive.sample.demo;

import android.app.Activity;
import android.content.Intent;
import android.content.IntentSender.SendIntentException;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

/**
 * An abstract activity that handles authorization and connection to the Drive
 * services.
 */
public abstract class BaseDemoActivity extends Activity implements
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener {
......

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Ho usato Google Plugin for Eclipse per installare le drive apis di google ma non compila uguale mi da questo errore:

GoogleApiClient cannot be resolved to a type

R.