Re-land: cc: Add raster finished signals to RasterWorkerPool.

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 c2fe39506fa34cfaebe81a4448a8e67a54136fdd..9f9a10e83c9b47f0e3ea679d0bea890c23febeb7 100644
--- a/cc/resources/image_raster_worker_pool.cc
+++ b/cc/resources/image_raster_worker_pool.cc
@@ -79,7 +79,9 @@ void ImageRasterWorkerPool::ScheduleTasks(RasterTask::Queue* queue) {
     TaskMap::iterator image_it = image_tasks_.find(task);
     if (image_it != image_tasks_.end()) {
       internal::WorkerPoolTask* image_task = image_it->second.get();
-      graph.InsertRasterTask(image_task, task->dependencies());
+      graph.InsertRasterTask(image_task,
+                             task->dependencies(),
+                             IsRasterTaskRequiredForActivation(task));
       continue;
     }
 
@@ -99,12 +101,22 @@ void ImageRasterWorkerPool::ScheduleTasks(RasterTask::Queue* queue) {
                        base::Unretained(this),
                        make_scoped_refptr(task))));
     image_tasks_[task] = new_image_task;
-    graph.InsertRasterTask(new_image_task.get(), task->dependencies());
+    graph.InsertRasterTask(new_image_task.get(),
+                           task->dependencies(),
+                           IsRasterTaskRequiredForActivation(task));
   }
 
   SetRasterTaskGraph(&graph);
 }
 
+void ImageRasterWorkerPool::OnRasterTasksFinished() {
+  client()->DidFinishedRunningTasks();
+}
+
+void ImageRasterWorkerPool::OnRasterTasksRequiredForActivationFinished() {
+  client()->DidFinishedRunningTasksRequiredForActivation();
+}
+
 void ImageRasterWorkerPool::OnRasterTaskCompleted(
     scoped_refptr<internal::RasterWorkerPoolTask> task,
     bool was_canceled) {