Hold a weak reference to PointerController when handling vsync

namespace android {

// --- WeakLooperCallback ---

class WeakLooperCallback: public LooperCallback {

protected:

    virtual ~WeakLooperCallback() { }

public:

    WeakLooperCallback(const wp<LooperCallback>& callback) :

        mCallback(callback) {

    }

    virtual int handleEvent(int fd, int events, void* data) {

        sp<LooperCallback> callback = mCallback.promote();

        if (callback != NULL) {

            return callback->handleEvent(fd, events, data);

        }

        return 0; // the client is gone, remove the callback

    }

private:

    wp<LooperCallback> mCallback;

};

// --- PointerController ---

// Time to wait before starting the fade when the pointer is inactive.

        const sp<Looper>& looper, const sp<SpriteController>& spriteController) :

        mPolicy(policy), mLooper(looper), mSpriteController(spriteController) {

    mHandler = new WeakMessageHandler(this);

    mCallback = new WeakLooperCallback(this);

    if (mDisplayEventReceiver.initCheck() == NO_ERROR) {

        mLooper->addFd(mDisplayEventReceiver.getFd(), Looper::POLL_CALLBACK,

                       Looper::EVENT_INPUT, this, nullptr);

                       Looper::EVENT_INPUT, mCallback, nullptr);

    } else {

        ALOGE("Failed to initialize DisplayEventReceiver.");

    }

    sp<Looper> mLooper;

    sp<SpriteController> mSpriteController;

    sp<WeakMessageHandler> mHandler;

    sp<LooperCallback> mCallback;

    DisplayEventReceiver mDisplayEventReceiver;