cc: Remove cc:RasterRequiredForActivation synthetic delays.

cc/resources/image_raster_worker_pool.cc

Index: cc/resources/image_raster_worker_pool.cc
diff --git a/cc/resources/image_raster_worker_pool.cc b/cc/resources/image_raster_worker_pool.cc
index d0f75e13b90c262e7f12498528b6ca3cad4ffd02..5cd42dabf0553fefa27856995485166fca8fe727 100644
--- a/cc/resources/image_raster_worker_pool.cc
+++ b/cc/resources/image_raster_worker_pool.cc
@@ -51,12 +51,6 @@ void ImageRasterWorkerPool::Shutdown() {
 void ImageRasterWorkerPool::ScheduleTasks(RasterTaskQueue* queue) {
   TRACE_EVENT0("cc", "ImageRasterWorkerPool::ScheduleTasks");
 
-  DCHECK_EQ(queue->required_for_activation_count,
-            static_cast<size_t>(
-                std::count_if(queue->items.begin(),
-                              queue->items.end(),
-                              RasterTaskQueue::Item::IsRequiredForActivation)));
-
   if (!raster_tasks_pending_)
     TRACE_EVENT_ASYNC_BEGIN0("cc", "ScheduledTasks", this);
 
@@ -71,19 +65,19 @@ void ImageRasterWorkerPool::ScheduleTasks(RasterTaskQueue* queue) {
   raster_finished_weak_ptr_factory_.InvalidateWeakPtrs();
 
   scoped_refptr<RasterizerTask>
-      new_raster_required_for_activation_finished_task(
-          CreateRasterRequiredForActivationFinishedTask(
-              queue->required_for_activation_count,
-              task_runner_.get(),
-              base::Bind(
-                  &ImageRasterWorkerPool::OnRasterRequiredForActivationFinished,
-                  raster_finished_weak_ptr_factory_.GetWeakPtr())));
+      new_raster_required_for_activation_finished_task(CreateRasterFinishedTask(
+          task_runner_.get(),
+          base::Bind(
+              &ImageRasterWorkerPool::OnRasterRequiredForActivationFinished,
+              raster_finished_weak_ptr_factory_.GetWeakPtr())));
   scoped_refptr<RasterizerTask> new_raster_finished_task(
       CreateRasterFinishedTask(
           task_runner_.get(),
           base::Bind(&ImageRasterWorkerPool::OnRasterFinished,
                      raster_finished_weak_ptr_factory_.GetWeakPtr())));
 
+  size_t required_for_activation_count = 0;
+
   for (RasterTaskQueue::Item::Vector::const_iterator it = queue->items.begin();
        it != queue->items.end();
        ++it) {
@@ -92,6 +86,7 @@ void ImageRasterWorkerPool::ScheduleTasks(RasterTaskQueue* queue) {
     DCHECK(!task->HasCompleted());
 
     if (item.required_for_activation) {
+      ++required_for_activation_count;
       graph_.edges.push_back(TaskGraph::Edge(
           task, new_raster_required_for_activation_finished_task.get()));
     }
@@ -105,7 +100,7 @@ void ImageRasterWorkerPool::ScheduleTasks(RasterTaskQueue* queue) {
   InsertNodeForTask(&graph_,
                     new_raster_required_for_activation_finished_task.get(),
                     kRasterRequiredForActivationFinishedTaskPriority,
-                    queue->required_for_activation_count);
+                    required_for_activation_count);
   InsertNodeForTask(&graph_,
                     new_raster_finished_task.get(),
                     kRasterFinishedTaskPriority,