Chromecast and Ezcast are both receivers, right? You connect them to HDMI inputs in TV sets and other devices. Then you use apps to send wireless video information to them, from your mobile devices, right? Even if there´s a computer software that would do the same job, Resolume would have to consider that software as a virtual output device. I don´t see that happening, but I may be wrong.
Also, there will be allways some wireless delay and the distance between your computer and the Chromecast device to consider.
In the other hand, I already did the opposite! I successfully captured mobile input into Resolume as source, from an EZCast device connected to a capture card.