Not for review - Rebase of crrev.com/62833003

LayoutTests/fast/workers/resources/bubble2.js

+(function(scope) {
+  'use strict';
+
+  var tokens = null;
+  var scroll = null;
+  var pendingscrolldelta = null;
+  var transform = null;
+
+  function sign(n) {
+    if (n >= 0)
+      return 1;
+    return -1;
+  }
+
+  // An extremely cheesy animation.
+  function tick(context) {
+      var seconds = context.timestamp / 1000.0;
+      var scrolltop = context.getScalar(scroll);
+      var psd = undefined;
+      try {
+        psd = context.getScalar(pendingscrolldelta);
+      } catch(err) {
+        console.log(err);
+      }
+
+      if (psd) {
+        // beforescroll
+        console.log('beforescroll pendingscrolldelta: ' + psd);
+
+        var matrix = context.getMatrix(transform);
+        matrix.m24 -= psd;
+        context.setMatrix(transform, matrix);
+        context.setScalar(pendingscrolldelta, 5 * sign(psd));
+        //context.setScalar(pendingscrolldelta, 0);
+      } else {
+        // normal
+        console.log('normal tick, scrolltop: ' + scrolltop);
+
+        //var matrix = context.getMatrix(transform);
+        //matrix.m24 = 0.5 * scrolltop; //Math.sin(seconds);
+        //context.setMatrix(transform, matrix);
+      }
+
+      scope.teleportMessage(context, tick);
+  }
+
+  scope.onmessage = function(e) {
+    tokens = e.data;
+    scroll = tokens[0];
+    pendingscrolldelta = tokens[1];
+    transform = tokens[2];
+    var context = new TeleportContext(tokens);
+    scope.teleportMessage(context, tick);
+  };
+
+})(self);