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.
Chromecast can cast the contents of a physical display right? Why not connect two small monitors to your computer and have them casted to the Projectors. You'll need to have two extra monitors but that's it. The lag, like posted above, will be quite noticeable though, but of it course depends on what you are trying to do wether that's an issue or not.
I think there are also Wireless HDMI Solutions but i don't have any experience with this.