Google's Android operating system currently supports Java as its first-class language, and sources say Swift is not meant to replace Java, at least initially. While the ongoing litigation with Oracle is likely cause for concern, sources say Google considers Swift to have a broader "upside" than Java.As outlined by The Next Web, adopting Swift would be a major undertaking for Google, due to the need to create a runtime for Swift and incorporate it into APIs and SDKs, many of which would need to be rewritten, but it is something that Google could do. A Swift-based Android operating system would be a boon for developers, who could create native apps for both platforms. Swift is a well-liked programming language because it's simple to learn, easy to work with, and fast.
Along with Google, Facebook and Uber are also said to be considering making Swift "more central" to their operations. At Facebook, employees are already working with Swift internally, though how deeply remains in question, and at Uber, it is not clear if work on a transition to Swift has begun.
Switching over to Swift would be a long process for Google that could span multiple months or years due to the need to rewrite Android services, apps, and APIs, so it is not likely to be adopted in the near future, and Android support is integral, says The Next Web, for the deep integration that Facebook and Uber want to adopt.
Apple first announced Swift in June of 2014 and expanded on it with Swift 2 in June of 2015. In December, the programming language was made open source.