The upcoming OnePlus Z will allegedly ship with a Qualcomm Snapdragon 765 SoC. Previous leaks hinted that the phone would feature MediaTek's Dimensity 1000 chip. OnePlus may have planned on using a MediaTek chip initially but switched to Qualcomm at the last moment.
https://www.notebookcheck.net/OnePlus-Z-likely-to-feature-Qualcomm-s-Snapdragon-765G-chip-instead-of-the-MediaTek-Dimensity-1000.463462.0.html