Merge "CompositionSamplingListener: weakly reference listener"

struct CompositionSamplingListener : public BnRegionSamplingListener {

    CompositionSamplingListener(JNIEnv* env, jobject listener)

            : mListener(env->NewGlobalRef(listener)) {}

            : mListener(env->NewWeakGlobalRef(listener)) {}

    void onSampleCollected(float medianLuma) override {

        JNIEnv* env = AndroidRuntime::getJNIEnv();

        LOG_ALWAYS_FATAL_IF(env == nullptr, "Unable to retrieve JNIEnv in onSampleCollected.");

        jobject listener = env->NewGlobalRef(mListener);

        if (listener == NULL) {

            // Weak reference went out of scope

            return;

        }

        env->CallStaticVoidMethod(gListenerClassInfo.mClass,

                gListenerClassInfo.mDispatchOnSampleCollected, mListener,

                gListenerClassInfo.mDispatchOnSampleCollected, listener,

                static_cast<jfloat>(medianLuma));

        env->DeleteGlobalRef(listener);

        if (env->ExceptionCheck()) {

            ALOGE("CompositionSamplingListener.onSampleCollected() failed.");

            LOGE_EX(env);

protected:

    virtual ~CompositionSamplingListener() {

        JNIEnv* env = AndroidRuntime::getJNIEnv();

        env->DeleteGlobalRef(mListener);

        env->DeleteWeakGlobalRef(mListener);

    }

private:

    jobject mListener;

    jweak mListener;

};

jlong nativeCreate(JNIEnv* env, jclass clazz, jobject obj) {