Eu tentei atualizarcom.android.support:appcompat ecom.android.support:design de: 25.0.1 a 25.1.0, da seguinte forma:

compile 'com.android.support:appcompat-v7:25.0.1'
compile 'com.android.support:design:25.0.1'

para:

compile 'com.android.support:appcompat-v7:25.1.0'
compile 'com.android.support:design:25.1.0'

mas descobri que meu botão de ação flutuante não aparece mais quando a atividade rola. Meu comportamento no FAB é definido pelo seguinte:

public class MyFabBehavior extends FloatingActionButton.Behavior {

    public MyFabBehavior(Context context, AttributeSet attrs) {
        super();
    }

    @Override
    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout,
                                       FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {

        // Ensure we react to vertical scrolling
        return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
                || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);

    }

    @Override
    public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child,
                               View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {

        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
        if (dyConsumed < 0) {
            // User scrolled up -> hide the FAB
            animateFab(child, View.GONE);
        } else if (dyConsumed > 0) {
            // User scrolled down -> show the FAB
            animateFab(child, View.VISIBLE);
        }
    }

    static public void animateFab(FloatingActionButton fab, int visibility) {
        // ignore visibility passed in, and just make fab visible regardless
        if (fab.getVisibility() != View.VISIBLE) {
            fab.show();
        }
    }
}

e meu layout é o seguinte:

<android.support.design.widget.CoordinatorLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"  >

    <android.support.v4.widget.NestedScrollView
        android:id="@+id/main_scrollview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:padding="8dp" >

        ...

    </android.support.v4.widget.NestedScrollView>

    <android.support.design.widget.FloatingActionButton
        app:layout_behavior="com.example.MyFabBehavior"
        android:id="@+id/fab"
        app:fabSize="normal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_marginBottom="@dimen/fab_margin"
        android:layout_marginRight="@dimen/fab_margin"
        android:onClick="saveButton"
        app:elevation="6dp"
        app:pressedTranslationZ="12dp"
        app:backgroundTint="@color/colorPrimary"
        android:src="@drawable/ic_done_white_24dp" />

</android.support.design.widget.CoordinatorLayout>