A Chinese Berlin Conference is held
The British grab the aforementioned territories, the Germans Shandong, the French Yunnan, and the Russians Manchuria, Mongolia, Inner Mongolia, and Xinjiang.
Whether or not a rump China can survive in Hunan, Sichuan, etc is a fair question. If so, I imagine it to be a really horrid place to live, with no connection to the sea, nothing much to trade, and full of bitter revanchist anger at the foreigners.
Japan might annex Manchuria in 1905, assuming it's a Russian colony, or else set up a puppet empire there like in 1933 OTL. Afterwards, they might end up throwing their lot in with the Germans in WWI, in the hopes of grabbing the Anglo-French Chinese colonies.
The British and French are more stretched by having to control another huge chunk of land, but are richer than OTL and have more access to Chinese resources.
In 1945, Taiwan will probably be given to the UK, even though it was never a British colony. The USSR will presumably still join the Pacific War in summer 1945, and will also likely have tremendous influence or even outright control over Xinjiang, as well as Mongolia. Maybe Manchuria is annexed directly into the USSR, maybe not.
When decolonisation comes, I imagine that different Chinese states will be set up at first (viz, the "Republic of Guangdong", etc), but seeing as how all of these new states are mostly ethnic Han and share a common heritage, I'd be willing to bet that unification will occur, perhaps by force under a Bismarck/Chiang Kai-shek like figure. The 1960s/70s TTL will look like the OTL Warlord era.
Meanwhile, the Soviets will be trying to get different Chinese states to go communist, with varying degrees of success.
Overall, China will still be a third-world country in 2019, and will look much more like Africa than the modern PRC. However, no Great Leap Forward is always a plus...