Bug 1444480 - Omit timezone in some timestamps. r=florian

--HG--
extra : rebase_source : a5c245dbbf79c2d751d8a6334c20050a0065acef

chat/content/imtooltip.xml

@@ -488,13 +488,13 @@
            let text;
            if ((new Date()).toDateString() == date.toDateString()) {
              const dateTimeFormatter = new Services.intl.DateTimeFormat(undefined, {
-               timeStyle: "long"
+               timeStyle: "medium"
              });
              text = dateTimeFormatter.format(date);
            }
            else {
              const dateTimeFormatter = new Services.intl.DateTimeFormat(undefined, {
-               dateStyle: "short", timeStyle: "long"
+               dateStyle: "short", timeStyle: "medium"
              });
              text = dateTimeFormatter.format(date);
            }

chat/modules/ToLocaleFormat.jsm

@@ -23,18 +23,18 @@ function ToLocaleFormat(aFormat, aDate) {
     return Day(t) - DayFromYear(t.getFullYear());
   }
   function weekday(option) {
-    return aDate.toLocaleString(locale, {weekday: option});
+    return aDate.toLocaleString(undefined, {weekday: option});
   }
   function month(option) {
-    return aDate.toLocaleString(locale, {month: option});
+    return aDate.toLocaleString(undefined, {month: option});
   }
   function hourMinSecTwoDigits() {
-    return aDate.toLocaleString(locale, {
+    return aDate.toLocaleString(undefined, {
       hour: "2-digit", minute: "2-digit", second: "2-digit"
     });
   }
   function dayPeriod() {
-    let dtf = Intl.Dateformat(locale, {hour: "2-digit"});
+    let dtf = Intl.DateTimeFormat(undefined, {hour: "2-digit"});
     let dayPeriodPart =
       dtf.resolvedOptions().hour12 &&
       dtf.formatToParts(aDate).find(part => part.type === "dayPeriod");
@@ -76,7 +76,7 @@ function ToLocaleFormat(aFormat, aDate) {
     return (offset < 0 ? "+" : "-") + String(tzoff).padStart(4, "0");
   }
   function timeZone() {
-    let dtf = Intl.DateTimeFormat("en-US", {timeZoneName: "short"});
+    let dtf = Intl.DateTimeFormat(undefined, {timeZoneName: "short"});
     let timeZoneNamePart = dtf.formatToParts(aDate)
                               .find(part => part.type === "timeZoneName");
     return timeZoneNamePart ? timeZoneNamePart.value : "";

chat/modules/imThemes.jsm

@@ -39,6 +39,14 @@ XPCOMUtils.defineLazyGetter(this, "TXTToHTML", function() {
   return aTXT => cs.scanTXT(aTXT, cs.kEntities);
 });
 
+XPCOMUtils.defineLazyGetter(this, "gTimeFormatter", () => {
+  return new Services.intl.DateTimeFormat(undefined, {
+    hour: "2-digit",
+    minute: "2-digit",
+    second: "2-digit"
+  });
+});
+
 ChromeUtils.defineModuleGetter(this,
   "ToLocaleFormat", "resource:///modules/ToLocaleFormat.jsm");
 
@@ -340,10 +348,7 @@ var headerFooterReplacements = {
     let date = new Date(aConv.startDate / 1000);
     if (aFormat)
       return ToLocaleFormat(aFormat, date);
-    const timeFormatter = new Services.intl.DateTimeFormat(undefined, {
-      timeStyle: "long"
-    });
-    return timeFormatter.format(date);
+    return gTimeFormatter.format(date);
   }
 };
 
@@ -361,17 +366,11 @@ var statusMessageReplacements = {
     let date = new Date(aMsg.time * 1000);
     if (aFormat)
       return ToLocaleFormat(aFormat, date);
-    const timeFormatter = new Services.intl.DateTimeFormat(undefined, {
-      timeStyle: "long"
-    });
-    return timeFormatter.format(date);
+    return gTimeFormatter.format(date);
   },
   timestamp: aMsg => aMsg.time,
   shortTime: function(aMsg) {
-    const timeFormatter = new Services.intl.DateTimeFormat(undefined, {
-      timeStyle: "long"
-    });
-    return timeFormatter.format(new Date(aMsg.time * 1000));
+    return gTimeFormatter.format(new Date(aMsg.time * 1000));
   },
   messageClasses: function(aMsg) {
     let msgClass = [];