Upボタンの実装メモ ref: http://qiita.com/nein37/items/6a063f5462400036920b

AndroidManifest.xml

        <activity
            android:name=".ChildActivity"
            android:launchMode="singleTop"
            android:parentActivityName=".ParentActivity">
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".ParentActivity" />
        </activity>

file0.java

    java.lang.IllegalArgumentException: Activity ACTIVITY_NAME does not have a parent activity name specified. (Did you forget to add the android.support.PARENT_ACTIVITY <meta-data>  element in your manifest?)

file2.java

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

file4.java

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                Intent upIntent = NavUtils.getParentActivityIntent(this);
                if (NavUtils.shouldUpRecreateTask(this, upIntent)) {
                    // 新しくタスクを生成する必要がある
                    TaskStackBuilder.create(this)
                            .addNextIntentWithParentStack(upIntent)
                            .startActivities();
                    finish();
                } else {
                    NavUtils.navigateUpTo(this, upIntent);
                }
                return true;
        }
        return super.onOptionsItemSelected(item);
    }