Backed out changeset ef1550969466 (bug 1357487) caused perf regressions & author didn't justified them CLOSED TREE

browser/app/profile/firefox.js

@@ -70,7 +70,10 @@ pref("extensions.geckoProfiler.getSymbolRules", "localBreakpad,dump_syms.exe");
 pref("extensions.webextensions.base-content-security-policy", "script-src 'self' https://* moz-extension: blob: filesystem: 'unsafe-eval' 'unsafe-inline'; object-src 'self' https://* moz-extension: blob: filesystem:;");
 pref("extensions.webextensions.default-content-security-policy", "script-src 'self'; object-src 'self';");
 
+#if defined(XP_WIN) || defined(XP_MACOSX)
 pref("extensions.webextensions.remote", true);
+#endif
+
 pref("extensions.webextensions.background-delayed-startup", true);
 
 // Extensions that should not be flagged as legacy in about:addons

browser/components/extensions/test/browser/browser_ext_browserAction_popup_preload.js

@@ -202,12 +202,10 @@ add_task(async function testBrowserActionTabPopulation() {
   let widget = getBrowserActionWidget(extension).forWindow(win);
   EventUtils.synthesizeMouseAtCenter(widget.node, {type: "mousedown", button: 0}, win);
 
-  await new Promise(resolve => setTimeout(resolve, 100));
+  await extension.awaitMessage("tabTitle");
 
   EventUtils.synthesizeMouseAtCenter(widget.node, {type: "mouseup", button: 0}, win);
 
-  await extension.awaitMessage("tabTitle");
-
   await extension.unload();
   await BrowserTestUtils.closeWindow(win);
 });