cc: Remove RasterWorkerPool::Task.

cc/resources/pixel_buffer_raster_worker_pool.cc

Index: cc/resources/pixel_buffer_raster_worker_pool.cc
diff --git a/cc/resources/pixel_buffer_raster_worker_pool.cc b/cc/resources/pixel_buffer_raster_worker_pool.cc
index 21ee1ccfbbe8849ccd6b5498a7ea322e13fc3278..3cf72f3468fdce0a890a0f07022d0775d91d15ba 100644
--- a/cc/resources/pixel_buffer_raster_worker_pool.cc
+++ b/cc/resources/pixel_buffer_raster_worker_pool.cc
@@ -88,9 +88,15 @@ void PixelBufferRasterWorkerPool::Shutdown() {
   DCHECK_EQ(completed_raster_tasks_.size(), raster_task_states_.size());
 }
 
-void PixelBufferRasterWorkerPool::ScheduleTasks(RasterTask::Queue* queue) {
+void PixelBufferRasterWorkerPool::ScheduleTasks(RasterTaskQueue* queue) {
   TRACE_EVENT0("cc", "PixelBufferRasterWorkerPool::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 (!should_notify_client_if_no_tasks_are_pending_)
     TRACE_EVENT_ASYNC_BEGIN0("cc", "ScheduledTasks", this);