chromium: Use upstream desktop entry

Upstream provides a much more featureful desktop entry file. If we use
that we take advantage of all of those features and don't have to maintain it
ourselves.

pkgs/applications/networking/browsers/chromium/browser.nix

@@ -38,6 +38,25 @@ mkChromiumDerivation (base: rec {
       mkdir -vp "$logo_output_path"
       cp -v "$icon_file" "$logo_output_path/$packageName.png"
     done
+
+    # Install Desktop Entry
+    install -D chrome/installer/linux/common/desktop.template \
+      $out/share/applications/chromium-browser.desktop
+
+    substituteInPlace $out/share/applications/chromium-browser.desktop \
+      --replace "@@MENUNAME@@" "Chromium" \
+      --replace "@@PACKAGE@@" "chromium" \
+      --replace "Exec=/usr/bin/@@USR_BIN_SYMLINK_NAME@@" "Exec=chromium"
+
+    # Append more mime types to the end
+    sed -i '/^MimeType=/ s,$,x-scheme-handler/webcal;x-scheme-handler/mailto;x-scheme-handler/about;x-scheme-handler/unknown,' \
+      $out/share/applications/chromium-browser.desktop
+
+    # See https://github.com/NixOS/nixpkgs/issues/12433
+    sed -i \
+      -e '/\[Desktop Entry\]/a\' \
+      -e 'StartupWMClass=chromium-browser' \
+      $out/share/applications/chromium-browser.desktop
   '';
 
   passthru = { inherit sandboxExecutableName; };

pkgs/applications/networking/browsers/chromium/default.nix

@@ -45,31 +45,6 @@ in let
     };
   };
 
-  desktopItem = makeDesktopItem {
-    name = "chromium-browser";
-    exec = "chromium %U";
-    icon = "chromium";
-    comment = "An open source web browser from Google";
-    desktopName = "Chromium";
-    genericName = "Web browser";
-    mimeType = stdenv.lib.concatStringsSep ";" [
-      "text/html"
-      "text/xml"
-      "application/xhtml+xml"
-      "x-scheme-handler/http"
-      "x-scheme-handler/https"
-      "x-scheme-handler/ftp"
-      "x-scheme-handler/mailto"
-      "x-scheme-handler/webcal"
-      "x-scheme-handler/about"
-      "x-scheme-handler/unknown"
-    ];
-    categories = "Network;WebBrowser";
-    extraEntries = ''
-      StartupWMClass=chromium-browser
-    '';
-  };
-
   suffix = if channel != "stable" then "-" + channel else "";
 
   sandboxExecutableName = chromium.browser.passthru.sandboxExecutableName;
@@ -135,7 +110,6 @@ in stdenv.mkDerivation {
     for f in '${chromium.browser}'/share/*; do # hello emacs */
       ln -s -t "$out/share/" "$f"
     done
-    cp -v "${desktopItem}/share/applications/"* "$out/share/applications"
   '';
 
   inherit (chromium.browser) packageName;