Google follows the rule "embrace, extinguish and extinct" of Microsoft. Chromium features (bookmark synchronization, safe-browsing feature, search suggestion, spell-checking, etc..) are provided by Google and are not a part of Chromium; but Google has long provided API keys for ditributors of Chromium builds to use. But as of March 15, non-Chrome builds of Chromium would lose access to these APIs.

As response, many Linux distributions may remove the chromium package from their dependancies.

this move on Google's part is just highlighting a situation that has existed for years already: you might use Chromium as a way of avoiding proprietary software, but if you use Chromium with features like synchronization, that objective has not been met. [...] Similar to Android: there is a core built with free software, but getting its full functionality requires accepting layers of proprietary code on top of it.