X11 or Wayland? What Chrome version are you using? Could be Bug 358277.

x11, chromium 99.0.4844.82, vivaldi 5.1.2567.73.

(In reply to Nate Graham from comment #1)
>Could be Bug 358277.
Maybe.

(In reply to Nate Graham from comment #1)
>Could be Bug 358277.

I tested on a clean profile in a virtual machine. There is no such bug. So it's in the settings of the current profile. What can influence this?

I understood what the problem is. And this is a big problem. A very long time ago I installed and selected a third party numix circle icon pack. Now I switched the icon theme to the default breeze and the problem with icons in chromium web apps is gone. I have a lot of icon themes installed, I tried to switch them and noticed a peculiarity. Icon themes with few icons do not have this bug. But in those icon themes in which many icons are drawn, this bug appears. How can this situation be corrected? I want to use a third party icon theme and have normal icons for chromium web apps.

I guess the issue is missing icons in those themes. You'd need to bug their creators.

(In reply to Nate Graham from comment #6)
> I guess the issue is missing icons in those themes. You'd need to bug their
> creators.

It's the other way around. There are small icon themes that implement a small basic set of icons. With these themes, this bug does not appear. In this case, everything works fine and there is no need to ask the author to draw new icons. There are also some of the largest icon themes, they have the largest number of icons. Here is an example of such a project https://numixproject.github.io it is one of the biggest icon set. I doubt very much that I should ask every author of icon themes (large themes) with which a bug manifests itself to draw new icons. It's pointless. We need to fix the bug.

It's a strange situation. Should I, for every new site I add as a web app via chromium or vivaldi, ask all big icon theme developers to draw new icons? This is madness...

As I understand it, in large icon themes, the chrome or vivaldi icon is registered for everything related to chrome or vivaldi (including web applications). And even if I manually add the icon of the site I need to the theme, it still won’t be picked up. This is exactly what needs to be corrected.

I found out that numix icon theme has an icon for google keep.  But for some reason it is not used for the web app.  I'm sure other big themes have an icon for google keep and don't use it either.

Here in this screenshot  https://imgur.com/819l6Ff you can see that the Vivaldi icon is displayed in the properties of the .desktop file. But if you open the icon selection window, then there is already the correct google keep icon. How is this possible? I think this is wrong.

The same goes for ticktick https://imgur.com/DSW0suc

*** Bug 452302 has been marked as a duplicate of this bug. ***

Re-opening because I believe this bug applies to my situation here. Maybe it's a new edge case.

I have multiple chromium profiles and I create a desktop file for each. Each desktop file gets their own icon, and specifies --user-data-dir in the cmdline. When I add --enable-features=WaylandWindowDecorations and --ozone-platform-hint=auto to my ~/.config/chromium-flags.conf, I no longer get the correct icon, just the default wayland yellow circle W. Otherwise the default chromium shows the correct icon with wayland.


Example desktop file:

~/.local/share/applications/chromium-extra.desktop

[Desktop Entry]
Version=1.0
Name=Chromium-Extra
GenericName=Web Browser
Exec=/usr/bin/chromium --class=Chromium-Extra --user-data-dir=/home/xxxx/chromium_profiles/extra %U
StartupNotify=true
Terminal=false
#Icon=chromium
Icon=/home/xxxx/chromium_profiles/_icons/Chromium_Logo-green.svg
Type=Application
Categories=Network;WebBrowser;
MimeType=application/pdf;application/rdf+xml;application/rss+xml;application/xhtml+xml;application/xhtml_xml;application/xml;image/gif;image/jpeg;image/png;image/webp;text/html;text/xml;x-scheme-handler/http;x-scheme-handler/https;
Actions=new-window;new-private-window;

[Desktop Action new-window]
Name=New Window
Exec=/usr/bin/chromium --class=Chromium-Extra --user-data-dir=/home/xxxx/chromium_profiles/extra

[Desktop Action new-private-window]
Name=New Incognito Window
Exec=/usr/bin/chromium --class=Chromium-Extra --user-data-dir=/home/xxxx/chromium_profiles/extra --incognito


Also note, I tried to see if a window rule could be a work-around but it doesn't work. If I detect window properties to add exact match for window class, it'll fill: "chromium (/home/xxx/chromium_profiles/extra)" and same if I add Desktop file name to Appearance & Fixes. 

Another note: after I launch the extra browser profile, for a few seconds the taskbar shows a window titled "Chromium-Extra" with the correct icon, alongside the additional windows (from the previous session) which have the yellow W icon. This disappears from the taskbar within a second or so.

I should have also mentioned: the desktop files and icons work fine with Xorg and with xwayland if I don't add the flags to chromium-flags.conf, so it's a wayland-specific issue.

This is an older bug report and the code has changed a lot since it was reported. There's a very good chance the issue you're experiencing is caused by something else, even if the outward symptoms look and feel the same. Can you please submit a new bug report? Thank you!