Bug 1511247 - Disabled devtools/client/accessibility/test/browser/browser_accessibility_panel_highlighter_multi_tab.js on Linux64 debug for frequent failures r=jmaher

Differential Revision: https://phabricator.services.mozilla.com/D21375

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

devtools/client/accessibility/test/browser/browser.ini

@@ -15,6 +15,7 @@ support-files =
 [browser_accessibility_mutations.js]
 [browser_accessibility_panel_highlighter.js]
 [browser_accessibility_panel_highlighter_multi_tab.js]
+skip-if = (os == 'linux' && debug && bits == 64) # Bug 1511247
 [browser_accessibility_relation_navigation.js]
 [browser_accessibility_reload.js]
 [browser_accessibility_sidebar.js]