LoginActivity.java

package org.michenux.yourappidea.home;

import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;

import org.michenux.yourappidea.R;

public class LoginActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);

        Toolbar mToolBar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(mToolBar);
        ActionBar actionBar = getSupportActionBar();
        if (actionBar != null) {
            actionBar.setDisplayHomeAsUpEnabled(true);
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                this.finish();
                return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Fragment fragment = getSupportFragmentManager().findFragmentByTag("googlePlusFragment");
        if (fragment != null) {
            fragment.onActivityResult(requestCode, resultCode, data);
        }
    }
}