Bug 1485969 - Enable titlebar rendering on Enlightenment desktop, r=jhorak

Differential Revision: https://phabricator.services.mozilla.com/D4755

--HG--
extra : moz-landing-system : lando

widget/gtk/nsWindow.cpp

@@ -7139,6 +7139,8 @@ nsWindow::GetSystemCSDSupportLevel() {
         // KDE Plasma
         } else if (strstr(currentDesktop, "KDE") != nullptr) {
             sCSDSupportLevel = CSD_SUPPORT_CLIENT;
+        } else if (strstr(currentDesktop, "Enlightenment") != nullptr) {
+            sCSDSupportLevel = CSD_SUPPORT_CLIENT;
         } else if (strstr(currentDesktop, "LXDE") != nullptr) {
             sCSDSupportLevel = CSD_SUPPORT_CLIENT;
         } else if (strstr(currentDesktop, "openbox") != nullptr) {