Add synthetic delay points for latency testing

cc/resources/raster_worker_pool_perftest.cc

Index: cc/resources/raster_worker_pool_perftest.cc
diff --git a/cc/resources/raster_worker_pool_perftest.cc b/cc/resources/raster_worker_pool_perftest.cc
index 1bf2e908166c97d310cd3c270cb0da68d97548c4..6d646d67670b19b738216974a2693db7bf63a617 100644
--- a/cc/resources/raster_worker_pool_perftest.cc
+++ b/cc/resources/raster_worker_pool_perftest.cc
@@ -75,9 +75,17 @@ class PerfRasterWorkerPool : public RasterWorkerPool {
     unsigned priority = 0;
     TaskGraph graph;
 
+    size_t raster_tasks_required_for_activation_count = 0u;
+    for (RasterTaskVector::const_iterator it = raster_tasks().begin();
+         it != raster_tasks().end(); ++it) {
+      if (IsRasterTaskRequiredForActivation(it->get()))
+        raster_tasks_required_for_activation_count++;
+    }
+
     scoped_refptr<internal::WorkerPoolTask>
         raster_required_for_activation_finished_task(
-            CreateRasterRequiredForActivationFinishedTask());
+            CreateRasterRequiredForActivationFinishedTask(
+                raster_tasks_required_for_activation_count));
     internal::GraphNode* raster_required_for_activation_finished_node =
         CreateGraphNodeForTask(
             raster_required_for_activation_finished_task.get(),