Show favicons in the call tree about profiler

[gregtatum]

This reminds me that some people on the tracking protection and privacy side were interested in the performance overhead of scripts by domain. This is sort of in that direction.

[gregtatum]

All of my profile's ResourceTables have empty icon columns. Does this need to be added in the Gecko Profiler or on the add-on? Or do we need to fetch those manually and shove them into the profile?

[mstange]

For JS from add-ons, we need help from the Gecko Profiler add-on to capture add-on icons. We also need it to capture the relevant add-on information to know what URLs belong to to what add-on.
For "webhosts", it's trickier. The old cleopatra would just do blindly assume <host>/favicon.ico had a relevant favicon, if I recall correctly.

[julienw]

The old cleopatra would just do blindly assume /favicon.ico had a relevant favicon, if I recall correctly.

I've looked at some websites today, some of them have nothing at <hostname>/favicon.ico but instead specifies the icon through a<link rel="shortcut icon"> element. Others have different icons.

So here are some examples FTR:

Examples without favicon:

• https://developer.mozilla.org/
• www.foofighters.com

Examples where there is a favicon:

• www.mozilla.org
• https://github.com
• https://www.google.com
• slack
• medium
• duckduckgo
• bugzilla

Examples were there is a different worst favicon than the shortcut icon:

• twitter
• deezer

[gregtatum]

Seems like the easiest approach would be to do the naive thing by attempting to fetch the file, if it's found use it, and see if people complain when certain favicons don't show up.

[julienw]

Yeah that's my approach too.

[julienw]

So there are 6 PR with 6 different approaches. They come from combining these characteristics:

• icons in a separate fixed columns or next to the function name
• use <img> or div with background-image. The former seems to hit a bug in Firefox that is difficult to reproduce with simpler testcases, where the image is always refreshed.
• use redux or not