[automerger skipped] Merge "migrate custom widgets in comply with plugin framework" into ub-launcher3-qt-future-dev
am: 2bcd26a23d -s ours
am skip reason: change_id I8a3d0fe2689ad5ba24b19309728bbad0b6287f71 with SHA1 c7a6c2979c is in history

Change-Id: Ieba78ffdb8864f9dbaf7c9bd4e38996e943b2e23