Convert StatTimer to an ES6 class

src/display/dom_utils.js

@@ -461,20 +461,14 @@ function isExternalLinkTargetSet() {
   }
 }
 
-var StatTimer = (function StatTimerClosure() {
-  function rpad(str, pad, length) {
-    while (str.length < length) {
-      str += pad;
-    }
-    return str;
-  }
-  function StatTimer() {
+class StatTimer {
+  constructor(enable = true) {
     this.started = Object.create(null);
     this.times = [];
-    this.enabled = true;
+    this.enabled = !!enable;
   }
-  StatTimer.prototype = {
-    time: function StatTimer_time(name) {
+
+  time(name) {
     if (!this.enabled) {
       return;
     }
@@ -482,8 +476,9 @@ var StatTimer = (function StatTimerClosure() {
       warn('Timer is already running for ' + name);
     }
     this.started[name] = Date.now();
-    },
-    timeEnd: function StatTimer_timeEnd(name) {
+  }
+
+  timeEnd(name) {
     if (!this.enabled) {
       return;
     }
@@ -497,29 +492,26 @@ var StatTimer = (function StatTimerClosure() {
     });
     // Remove timer from started so it can be called again.
     delete this.started[name];
-    },
-    toString: function StatTimer_toString() {
-      var i, ii;
-      var times = this.times;
-      var out = '';
+  }
+
+  toString() {
+    let times = this.times;
     // Find the longest name for padding purposes.
-      var longest = 0;
-      for (i = 0, ii = times.length; i < ii; ++i) {
-        var name = times[i]['name'];
+    let out = '', longest = 0;
+    for (let i = 0, ii = times.length; i < ii; ++i) {
+      let name = times[i]['name'];
       if (name.length > longest) {
         longest = name.length;
       }
     }
-      for (i = 0, ii = times.length; i < ii; ++i) {
-        var span = times[i];
-        var duration = span.end - span.start;
-        out += rpad(span['name'], ' ', longest) + ' ' + duration + 'ms\n';
+    for (let i = 0, ii = times.length; i < ii; ++i) {
+      let span = times[i];
+      let duration = span.end - span.start;
+      out += `${span['name'].padEnd(longest)} ${duration}ms\n`;
     }
     return out;
-    },
-  };
-  return StatTimer;
-})();
+  }
+}
 
 export {
   CustomStyle,