cc: Rasterize cheap tiles immediately

cc/raster_worker_pool.cc

Index: cc/raster_worker_pool.cc
diff --git a/cc/raster_worker_pool.cc b/cc/raster_worker_pool.cc
index 13113b5f1bfde8bf7289a9d32bad34de8d86ad99..9e9bb88f826ec49b2473d8f24ad052c50c048e0d 100644
--- a/cc/raster_worker_pool.cc
+++ b/cc/raster_worker_pool.cc
@@ -22,12 +22,18 @@ class RasterWorkerPoolTaskImpl : public internal::WorkerPoolTask {
   }
 
   virtual void Run(RenderingStats* rendering_stats) OVERRIDE {
-    task_.Run(picture_pile_.get(), rendering_stats);
+    task_.Run(picture_pile_, rendering_stats);
     base::subtle::Release_Store(&completed_, 1);
   }
 
+  virtual void DeferToThread(base::Thread* thread) OVERRIDE {
+    picture_pile_clone_ = picture_pile_ =
+        picture_pile_->GetCloneForDrawingOnThread(thread);

[reveman, 2013/02/14 21:10:49]

DCHECK(!picture_pile_clone_) before this statement? maybe this does the right
thing when called multiple times but I think we should still check that it
doesn't happen.

[Sami, 2013/02/15 16:41:22]

Good idea. This handles multiple calls fine, but we only expect it to be called
once.

+  }
+
  private:
-  scoped_refptr<PicturePileImpl> picture_pile_;
+  PicturePileImpl* picture_pile_;
+  scoped_refptr<PicturePileImpl> picture_pile_clone_;
   RasterWorkerPool::RasterCallback task_;
 };
 
@@ -42,18 +48,20 @@ RasterWorkerPool::~RasterWorkerPool() {
 }
 
 void RasterWorkerPool::PostRasterTaskAndReply(PicturePileImpl* picture_pile,
+                                              bool is_cheap,
                                               const RasterCallback& task,
                                               const base::Closure& reply) {
-  Worker* worker = GetWorkerForNextTask();
+  scoped_ptr<internal::WorkerPoolTask> worker_task(
+      new RasterWorkerPoolTaskImpl(picture_pile, task, reply));
 
-  scoped_refptr<PicturePileImpl> picture_pile_clone =
-      picture_pile->GetCloneForDrawingOnThread(worker);
+  if (is_cheap && CanPostCheapTask()) {
+    PostCheapTask(worker_task.Pass());
+    return;
+  }
 
-  worker->PostTask(
-      make_scoped_ptr(new RasterWorkerPoolTaskImpl(
-                          picture_pile_clone.get(),
-                          task,
-                          reply)).PassAs<internal::WorkerPoolTask>());
+  Worker* worker = GetWorkerForNextTask();
+  worker_task->DeferToThread(worker);

[reveman, 2013/02/14 21:10:49]

can we call this from WorkerPool::Worker::PostTask instead and not have this
code make the assumption that a Worker is base::thread?

[Sami, 2013/02/15 16:41:22]

Yeah, that's much cleaner.

+  worker->PostTask(worker_task.Pass());
 }
 
 }  // namespace cc