Bug 1573804 - Fix dropdown tooltip arrow RTL alignment in devtools HTML documents. r=ntim

Differential Revision: https://phabricator.services.mozilla.com/D42538

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

devtools/client/themes/tooltips.css

@@ -222,12 +222,14 @@ strong {
   flex-shrink: 0;
 }
 
-/* In RTL locales, only use RTL on the tooltip content, keep LTR for positioning */
-.tooltip-container:-moz-locale-dir(rtl) {
+/* In RTL locales and context, only use RTL on the tooltip content, keep LTR for positioning */
+.tooltip-container:-moz-locale-dir(rtl),
+.tooltip-container:dir(rtl) {
   direction: ltr;
 }
 
-.tooltip-panel:-moz-locale-dir(rtl) {
+.tooltip-panel:-moz-locale-dir(rtl),
+.tooltip-panel:dir(rtl) {
   direction: rtl;
 }