Abstract ActionBar with Dagger (from Architecting Android Applications with Dagger - Jake Wharton)

SignUpActivity.java

public class SignUpActivity extends Activity {
    
    private final ObjectGraph childOg;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState):
        
        ExampleApp app = (ExampleApp) getApplication();
        ObjectGraph og = app.getObjectGraph();
        
        childOg = og.plus(new SignUpModule(this));
        
        // Content set up and injection
    }
}

SignUpModule.java

@Module (
    injects = {
        SignUpView.class, ForgotPasswordView.class
    }
)
public class SignUpModule {

    private final SignUpActivity signUpActivity;

    public SignUpModule(SignUpActivity signUpActivity) {
        this.signUpActivity = signUpActivity;
    }

    @Provides
    @Singleton
    ActionBar provideActionBar() {
        return signUpActivity.getActionBar();
    }
}

SignUpView.java

public class SignUpView extends LinearLayout {
    
    @Inject ActionBar actionBar;
    
    public SignUpView(Context context, AttributeSet attrs) {
        super(context, attrs);
        // Note: Injection happens by parent activity
    }
    
    @Override
    public void onAttachedToWindow() {
        super.onAttachedToWindow();
        actionBar.setTitle(R.string.sign_up);
    }
}

Buscando algún ejemplito por Google me encuentro con esto. Y al rato de estar ojeándolo me veo que es tuyo Fede :p
Me ha venido bien para refrescar, gracias! jeje