Merge "TransactionCallbacks: don't send callbacks until applied" into qt-dev

    }

    mTransactionCompletedThread.addPresentFence(mPreviousPresentFences[0]);

    // Lock the mStateLock in case SurfaceFlinger is in the middle of applying a transaction.

    // If we do not lock here, a callback could be sent without all of its SurfaceControls and

    // metrics.

    {

        Mutex::Autolock _l(mStateLock);

        mTransactionCompletedThread.sendCallbacks();

    }

    if (mLumaSampling && mRegionSamplingThread) {

        mRegionSamplingThread->notifyNewContent();