Not for review - Rebase of crrev.com/62833003

LayoutTests/fast/workers/resources/jank.js

+(function(scope) {
+  'use strict';
+
+  var tokens = null;
+  var transform = null;
+  var opacity = null;
+  var scroll = null;
+
+  // An extremely cheesy animation.
+  function tick(context) {
+      var seconds = context.timestamp / 1000.0;
+      var matrix = context.getMatrix(transform);
+      matrix.m41 = 200.0 + 100 * Math.sin(seconds);
+
+      context.setMatrix(transform, matrix);
+      context.setScalar(opacity, 0.5 + 0.5 * (Math.sin(seconds * 2.0)));
+      context.setScalar(scroll, 200.0 + 100.0 * (Math.sin(seconds * 0.75)));
+
+      scope.teleportMessage(context, tick);
+  }
+
+  scope.onmessage = function(e) {
+    tokens = e.data;
+    transform = tokens[0];
+    opacity = tokens[1];
+    scroll = tokens[2];
+    var context = new TeleportContext(tokens);
+    scope.teleportMessage(context, tick);
+  };
+
+})(self);