cc: GPU rasterize tiles synchronously in PrepareToDraw

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index ea30d8517395eed55d388bf2db0c7048ea3c3353..b3e1a6f8ae44364142695225cd868f2e2df321ed 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -312,7 +312,7 @@ void LayerTreeHostImpl::CommitComplete() {
     // more lazily when needed prior to drawing.
     sync_tree()->UpdateDrawProperties();
     // Start working on newly created tiles immediately if needed.
-    if (tile_manager_ && tile_priorities_dirty_)
+    if (tile_manager_ && tile_priorities_dirty_ && !use_gpu_rasterization_)
       ManageTiles();
     else
       NotifyReadyToActivate();
@@ -386,11 +386,23 @@ void LayerTreeHostImpl::Animate(base::TimeTicks monotonic_time) {
   AnimateTopControls(monotonic_time);
 }
 
+void LayerTreeHostImpl::RasterizeTiles() {
+  if (!tile_manager_)
+    return;
+  if (!tile_priorities_dirty_)
+    return;
+
+  tile_priorities_dirty_ = false;
+  tile_manager_->RasterizeTiles(global_tile_state_);
+}
+
 void LayerTreeHostImpl::ManageTiles() {
   if (!tile_manager_)
     return;
   if (!tile_priorities_dirty_)
     return;
+  if (use_gpu_rasterization_)
+    return;
 
   tile_priorities_dirty_ = false;
   tile_manager_->ManageTiles(global_tile_state_);
@@ -1070,6 +1082,9 @@ DrawResult LayerTreeHostImpl::PrepareToDraw(FrameData* frame) {
   bool ok = active_tree_->UpdateDrawProperties();
   DCHECK(ok) << "UpdateDrawProperties failed during draw";
 
+  if (use_gpu_rasterization_)
+    RasterizeTiles();
+
   frame->render_surface_layer_list = &active_tree_->RenderSurfaceLayerList();
   frame->render_passes.clear();
   frame->render_passes_by_id.clear();
@@ -1863,7 +1878,7 @@ void LayerTreeHostImpl::SetVisible(bool visible) {
 
   // Evict tiles immediately if invisible since this tab may never get another
   // draw or timer tick.
-  if (!visible_)
+  if (!visible_ && !use_gpu_rasterization_)
     ManageTiles();
 
   if (!renderer_)
@@ -1957,8 +1972,8 @@ void LayerTreeHostImpl::CreateAndSetTileManager() {
   DCHECK(output_surface_);
   DCHECK(resource_provider_);
 
-  CreateResourceAndRasterWorkerPool(
-      &raster_worker_pool_, &resource_pool_, &staging_resource_pool_);
+  CreateResourceAndRasterWorkerPool(&raster_worker_pool_, &gpu_rasterizer_,
+                                    &resource_pool_, &staging_resource_pool_);
   DCHECK(raster_worker_pool_);
   DCHECK(resource_pool_);
 
@@ -1969,18 +1984,17 @@ void LayerTreeHostImpl::CreateAndSetTileManager() {
   size_t scheduled_raster_task_limit =
       IsSynchronousSingleThreaded() ? std::numeric_limits<size_t>::max()
                                     : settings_.scheduled_raster_task_limit;
-  tile_manager_ = TileManager::Create(this,
-                                      task_runner,
-                                      resource_pool_.get(),
-                                      raster_worker_pool_->AsRasterizer(),
-                                      rendering_stats_instrumentation_,
-                                      scheduled_raster_task_limit);
+  tile_manager_ = TileManager::Create(
+      this, task_runner, resource_pool_.get(),
+      raster_worker_pool_->AsRasterizer(), gpu_rasterizer_.get(),
+      rendering_stats_instrumentation_, scheduled_raster_task_limit);
 
   UpdateTileManagerMemoryPolicy(ActualManagedMemoryPolicy());
 }
 
 void LayerTreeHostImpl::CreateResourceAndRasterWorkerPool(
     scoped_ptr<RasterWorkerPool>* raster_worker_pool,
+    scoped_ptr<GpuRasterizer>* gpu_rasterizer,
     scoped_ptr<ResourcePool>* resource_pool,
     scoped_ptr<ResourcePool>* staging_resource_pool) {
   base::SingleThreadTaskRunner* task_runner =
@@ -2013,6 +2027,11 @@ void LayerTreeHostImpl::CreateResourceAndRasterWorkerPool(
                                     context_provider,
                                     resource_provider_.get(),
                                     settings_.use_distance_field_text);
+
+    *gpu_rasterizer =
+        GpuRasterizer::Create(context_provider, resource_provider_.get(),
+                              settings_.use_distance_field_text);
+
     return;
   }
 
@@ -2079,6 +2098,7 @@ void LayerTreeHostImpl::DestroyTileManager() {
   resource_pool_ = nullptr;
   staging_resource_pool_ = nullptr;
   raster_worker_pool_ = nullptr;
+  gpu_rasterizer_ = nullptr;
   single_thread_synchronous_task_graph_runner_ = nullptr;
 }