Several people have asked me where did the Save-For-Web feature go? Well it is going away, but it has been moved...
This according to Adobe: As of the 2015 release of Photoshop CC, the File > Save For Web option has been moved to File > Export > Save For Web (Legacy) alongside newer export options.
Reasons are is that Save-For-Web is working on really old code, and needs to be updated. And there are a few things that down work right, like color shift issues. Adobe is not going to take it away with out a worthy replacement so for now, it is still very useable and still works like it always has.
The big news is the new Export As Workflows feature which is more in line with the need to export multiple assets out of Photoshop for all types of repsonsive web and mobile devices but it steps it up by allowing you to add things like padding to an image and exporting paths and vector shapes to SVG. It also allows a single layer or an entire document to be easily export in multiple formats, at multiple sizes and resolutions much faster and efficiently.
By naming a layers, for example: Car_4.jpg, Car_4b.png, Car_4c.png you can use the export feature to automatically with those names in those formats. If you want different size, name the layer: 200% Car_4.jpg and you end up with JPG twice the original size.
Here is the link from Adobe TV showing the features of Image asset generator in the Export As Workflows: