[GH-317] Correct size for Linux tray icons (#1595)

Signed-off-by: Elsie Hupp <9206310+elsiehupp@users.noreply.github.com>

src/assets/linux/ICONS.md

@@ -0,0 +1,3 @@
+## Figma
+
+Canonical vector source images for icons can be found on [Figma](https://www.figma.com/file/7V9FN9l9c4zHIls2ZUCoPU/MM-30584-Desktop-App-Icon-Update?node-id=9%3A1170). The files on GitHub are exports.

src/main/tray/tray.js

@@ -44,19 +44,18 @@ export function refreshTrayImages(trayIconTheme) {
     }
     case 'linux':
     {
-        const theme = trayIconTheme;
-        try {
+        if (trayIconTheme.equals('dark')) {
             trayImages = {
-                normal: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', theme, 'MenuIcon.png')),
-                unread: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', theme, 'MenuIconUnread.png')),
-                mention: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', theme, 'MenuIconMention.png')),
+                normal: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'top_bar_dark_16.png')),
+                unread: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'top_bar_dark_unread_16.png')),
+                mention: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'top_bar_dark_mention_16.png')),
             };
-        } catch (e) {
+        } else {
             //Fallback for invalid theme setting
             trayImages = {
-                normal: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'light', 'MenuIcon.png')),
-                unread: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'light', 'MenuIconUnread.png')),
-                mention: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'light', 'MenuIconMention.png')),
+                normal: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'top_bar_light_16.png')),
+                unread: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'top_bar_light_unread_16.png')),
+                mention: nativeImage.createFromPath(path.resolve(assetsDir, 'linux', 'top_bar_light_mention_16.png')),
             };
         }
         break;