cc: Change the activation/ready for draw check from layer to queue.

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 1185 matching lines @@
 
 scoped_ptr<RasterTilePriorityQueue> LayerTreeHostImpl::BuildRasterQueue(
     TreePriority tree_priority,
     RasterTilePriorityQueue::Type type) {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::BuildRasterQueue");
   picture_layer_pairs_.clear();
   GetPictureLayerImplPairs(&picture_layer_pairs_, true);
   scoped_ptr<RasterTilePriorityQueue> queue(RasterTilePriorityQueue::Create(
       picture_layer_pairs_, tree_priority, type));
 
-  if (!queue->IsEmpty()) {
-    // Only checking the Top() tile here isn't a definite answer that there is
-    // or isn't something required for draw in this raster queue. It's just a
-    // heuristic to let us hit the common case and proactively tell the
-    // scheduler that we expect to draw within each vsync until we get all the
-    // tiles ready to draw. If we happen to miss a required for draw tile here,
-    // then we will miss telling the scheduler each frame that we intend to draw
-    // so it may make worse scheduling decisions.
-    required_for_draw_tile_is_top_of_raster_queue_ =
-        queue->Top()->required_for_draw();
-  } else {
-    required_for_draw_tile_is_top_of_raster_queue_ = false;
+  // Only check whether the top tile is required for draw if we're not building
+  // a required for activation queue.
+  // TODO(vmpstr): Remove side-effects from this function. crbug.com/451147
+  if (type != RasterTilePriorityQueue::Type::REQUIRED_FOR_ACTIVATION) {
+    if (!queue->IsEmpty()) {
+      // Only checking the Top() tile here isn't a definite answer that there is
+      // or isn't something required for draw in this raster queue. It's just a
+      // heuristic to let us hit the common case and proactively tell the
+      // scheduler that we expect to draw within each vsync until we get all the
+      // tiles ready to draw. If we happen to miss a required for draw tile
+      // here, then we will miss telling the scheduler each frame that we intend
+      // to draw so it may make worse scheduling decisions.
+      required_for_draw_tile_is_top_of_raster_queue_ =
+          queue->Top()->required_for_draw();
+    } else {
+      required_for_draw_tile_is_top_of_raster_queue_ = false;
+    }
   }
   return queue;
 }
 
 scoped_ptr<EvictionTilePriorityQueue> LayerTreeHostImpl::BuildEvictionQueue(
     TreePriority tree_priority) {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::BuildEvictionQueue");
   scoped_ptr<EvictionTilePriorityQueue> queue(new EvictionTilePriorityQueue);
   picture_layer_pairs_.clear();
   GetPictureLayerImplPairs(&picture_layer_pairs_, false);
@@ skipping 2226 matching lines @@
 }
 
 void LayerTreeHostImpl::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
   std::vector<PictureLayerImpl*>::iterator it =
       std::find(picture_layers_.begin(), picture_layers_.end(), layer);
   DCHECK(it != picture_layers_.end());
   picture_layers_.erase(it);
 }
 
 }  // namespace cc