cc: Rework how picture layer tiling set gets into raster queues.

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 86401a7dca992c469fca2e80606a9aeac99ff513..a13ed4a65897cca6c969eb14f987350c5a25a55c 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1205,54 +1205,8 @@ void LayerTreeHostImpl::DidModifyTilePriorities() {
   client_->SetNeedsPrepareTilesOnImplThread();
 }
 
-void LayerTreeHostImpl::GetPictureLayerImplPairs(
-    std::vector<PictureLayerImpl::Pair>* layer_pairs,
-    bool need_valid_tile_priorities) const {
-  DCHECK(layer_pairs->empty());
-
-  for (auto& layer : active_tree_->picture_layers()) {
-    if (need_valid_tile_priorities && !layer->HasValidTilePriorities())
-      continue;
-    PictureLayerImpl* twin_layer = layer->GetPendingOrActiveTwinLayer();
-    // Ignore the twin layer when tile priorities are invalid.
-    if (need_valid_tile_priorities && twin_layer &&
-        !twin_layer->HasValidTilePriorities()) {
-      twin_layer = nullptr;
-    }
-    layer_pairs->push_back(PictureLayerImpl::Pair(layer, twin_layer));
-  }
-
-  if (pending_tree_) {
-    for (auto& layer : pending_tree_->picture_layers()) {
-      if (need_valid_tile_priorities && !layer->HasValidTilePriorities())
-        continue;
-      if (layer->GetPendingOrActiveTwinLayer()) {
-        // Already captured from the active tree.
-        continue;
-      }
-      layer_pairs->push_back(PictureLayerImpl::Pair(nullptr, layer));
-    }
-  }
-}
-
-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);
-  return RasterTilePriorityQueue::Create(picture_layer_pairs_, tree_priority,
-                                         type);
-}
-
-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);
-  queue->Build(picture_layer_pairs_, tree_priority);
-  return queue;
+bool LayerTreeHostImpl::PendingTreeExists() {
+  return !!pending_tree();
 }
 
 void LayerTreeHostImpl::SetIsLikelyToRequireADraw(