Merge "Wait until old ComposerClient is fully destroyed before recreating" into qt-dev

            // inverted (create and then destroy). Wait for a brief period to

            // see if the existing client is destroyed.

            ALOGD("waiting for previous client to be destroyed");

            mClientDestroyedCondition.wait_for(

                lock, 1s, [this]() -> bool { return mClient.promote() == nullptr; });

            if (mClient.promote() != nullptr) {

            mClientDestroyedCondition.wait_for(lock, 1s,

                                               [this]() -> bool { return mClient == nullptr; });

            if (mClient != nullptr) {

                ALOGD("previous client was not destroyed");

            } else {

                mClient.clear();

            }

        }