WIP - compositor worker mega patch.

third_party/WebKit/ManualTests/compositor-worker/parallax.js

+(function(scope) {
+  "use strict";
+
+  scope.isMain = function() {
+    return scope.window;
+  };
+
+  scope.tick = function(timestamp) {
+    console.log("tick (scrollTop = " + scroller.scrollTop + ", transform = " +
+        bg.transform + ")");
+    var t = bg.transform;
+    t.m42 = Math.round(scroller.scrollTop);
+    bg.transform = t;
+    var t = bg_parallax.transform;
+    t.m42 = 0.8 * scroller.scrollTop;
+    bg_parallax.transform = t;
+    scope.requestAnimationFrame(tick);
+  };
+
+  scope.initWorker = function() {
+    console.log("init worker");
+
+    self.onmessage = function(e) {
+      console.log("onmessage");
+
+      scope.scroller = e.data[0];
+      scope.bg = e.data[1];
+      scope.bg_parallax = e.data[2];
+
+      scope.requestAnimationFrame(tick);
+    };
+  };
+
+  scope.initMain = function() {
+    console.log("init main");
+
+    scope.worker = new CompositorWorker("parallax.js");
+
+    scope.scroller = new CompositorProxy(document.getElementById("scroller"), ['scrollTop']);
+    scope.bg = new CompositorProxy(document.getElementById("bg"), ['transform']);
+    scope.bg_parallax = new CompositorProxy(document.getElementById("bg-parallax"), ['transform']);
+
+    worker.postMessage([scroller, bg, bg_parallax]);
+  };
+
+  if (isMain())
+    initMain();
+  else
+    initWorker();
+})(self);