Background information
media-list doesn't include the exact image URLs that will be requested by mobile-html, only the original file name. This makes it difficult to save a page for offline without knowing the internal implementation details of mobile-html and how to construct the thumbnail URL at the correct size.
What
Add the exact image URLs to media-list
How
Pull the src and srcset from all image tags.
I'd imagine a structure along the lines of:
[ // list of all images
{
srcset: [
{src: //upload.wikimedia.org/wikipedia/commons/thumb/6/69/Dog_morphological_variation.png/640px-Dog_morphological_variation.png, scale: 1x}, // import src as 1x if 1x isn't in srcset
{src: //upload.wikimedia.org/wikipedia/commons/thumb/6/69/Dog_morphological_variation.png/640px-Dog_morphological_variation.png, scale: 1.5x}
]
},
{
srcset: [
{src: //upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Dog_anatomy_lateral_skeleton_view.jpg/640px-Dog_anatomy_lateral_skeleton_view.jpg, scale: 1x},
{src: //upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Dog_anatomy_lateral_skeleton_view.jpg/960px-Dog_anatomy_lateral_skeleton_view.jpg, scale: 1.5x},
{src: //upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Dog_anatomy_lateral_skeleton_view.jpg/1280px-Dog_anatomy_lateral_skeleton_view.jpg, scale: 2x}
]
}
]