As part of bug 7911, we came up with the following lists of icons needed for the native clients:
* Linux: 16, 22, 24, 32, 48, 64, 128
* Windows: 16, 24, 32, 48, 256
* Mac: 16, 32, 128, 256, 512
At least on Linux, we can see that Chrome and Edge places the following icons in the folder .local/share/icons/hicolor:
* 16, 32, 48, 128, 256, 512
Note that currently, size 128 is scaled down from our 144 icon, and size 256 is scaled up from our 192 icon.
Due to bug 8038, we can't include all the above sizes in our ICO. Ideally, the sizes for the native clients and the ones provided by the browsers should match.
*** Bug 8038 has been marked as a duplicate of this bug. ***
One solution to this bug is by using manifests, which also will solve the duplicate issue in bug 8038.
Further, if we start using manifest files, we will be able to use maskable icons:
Note that using a manifest will likely allow us to remove icons from our ICO.