user_perf("privacy.userContext.enabled", true);
user_perf("privacy.userContext.ui.enabled", true);
user_pref("browser.ctrlTab.previews", true);
user_pref("browser.fixup.alternate.enabled", false);
user_pref("browser.newtab.url", "https://www.google.co.nz");
user_pref("browser.tabs.tabClipWidth", 1);
user_pref("datareporting.healthreport.service.enabled", false);
user_pref("datareporting.healthreport.uploadEnabled", false);
user_pref("devtools.webconsole.persistlog", true);
user_pref("extensions.pocket.enabled", false);
user_pref("general.useragent.locale", "en-GB");
user_pref("layout.spellcheckDefault", 2);
user_pref("loop.enabled", false);
user_pref("plugins.click_to_play", true);
user_pref("spellchecker.dictionary", "en-GB");
user_pref("toolkit.telemetry.enabled", false);

user_perf("privacy.userContext.enabled", true);
user_perf("privacy.userContext.ui.enabled", true);
user_pref("browser.ctrlTab.previews", true);
user_pref("browser.fixup.alternate.enabled", false);
user_pref("browser.newtab.url", "https://www.google.co.nz");
user_pref("browser.tabs.tabClipWidth", 1);
user_pref("datareporting.healthreport.service.enabled", false);
user_pref("datareporting.healthreport.uploadEnabled", false);
user_pref("devtools.webconsole.persistlog", true);
user_pref("extensions.pocket.enabled", false);
user_pref("general.useragent.locale", "en-GB");
user_pref("layout.spellcheckDefault", 2);
user_pref("loop.enabled", false);
user_pref("media.block-autoplay-until-in-foreground", true);
user_pref("plugins.click_to_play", true);
user_pref("spellchecker.dictionary", "en-GB");
user_pref("toolkit.telemetry.enabled", false);

Stop videos auto playing in the background.
Stop videos auto playing in the background.
