cc: Do not ignore layers without valid priorities during eviction.

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 1247 matching lines @@
   tile_priorities_dirty_ = true;
   client_->SetNeedsManageTilesOnImplThread();
 }
 
 void LayerTreeHostImpl::DidInitializeVisibleTile() {
   if (client_ && !client_->IsInsideDraw())
     client_->DidInitializeVisibleTileOnImplThread();
 }
 
 void LayerTreeHostImpl::GetPictureLayerImplPairs(
-    std::vector<PictureLayerImpl::Pair>* layer_pairs) const {
+    std::vector<PictureLayerImpl::Pair>* layer_pairs,
+    bool need_valid_tile_priorities) const {
   DCHECK(layer_pairs->empty());
   for (std::vector<PictureLayerImpl*>::const_iterator it =
            picture_layers_.begin();
        it != picture_layers_.end();
        ++it) {
     PictureLayerImpl* layer = *it;
 
-    // TODO(vmpstr): Iterators and should handle this instead. crbug.com/381704
-    if (!layer->HasValidTilePriorities())
+    if (need_valid_tile_priorities && !layer->HasValidTilePriorities())

[vmpstr, 2014/10/31 15:35:49]

I think this is accepting too many layers. layer->HasValidTilePriorities would
return false in two situations: layer is recycled, or layer is not in render
surface layer list (rsll). If the layer is recycled we still want to skip it,
since it can't have unshared tiles (or at least if it does then that's a
separate bug). We only want to capture layers that are on either active or
pending tree but are not in rsll.

[USE eero AT chromium.org, 2014/11/04 17:47:57]

Yes, you are right. Fixed.

       continue;
 
     PictureLayerImpl* twin_layer = layer->GetPendingOrActiveTwinLayer();
 
     // Ignore the twin layer when tile priorities are invalid.
-    // TODO(vmpstr): Iterators should handle this instead. crbug.com/381704
-    if (twin_layer && !twin_layer->HasValidTilePriorities())
+    if (need_valid_tile_priorities && twin_layer &&
+        !twin_layer->HasValidTilePriorities())
       twin_layer = NULL;
 
     // If the current tree is ACTIVE_TREE, then always generate a layer_pair.
     // If current tree is PENDING_TREE, then only generate a layer_pair if
     // there is no twin layer.
     if (layer->GetTree() == ACTIVE_TREE) {
       DCHECK(!twin_layer || twin_layer->GetTree() == PENDING_TREE);
       layer_pairs->push_back(PictureLayerImpl::Pair(layer, twin_layer));
     } else if (!twin_layer) {
+      DCHECK(layer->GetTree() == PENDING_TREE);
       layer_pairs->push_back(PictureLayerImpl::Pair(NULL, layer));
     }
   }
 }
 
 void LayerTreeHostImpl::BuildRasterQueue(RasterTilePriorityQueue* queue,
                                          TreePriority tree_priority) {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::BuildRasterQueue");
   picture_layer_pairs_.clear();
-  GetPictureLayerImplPairs(&picture_layer_pairs_);
+  GetPictureLayerImplPairs(&picture_layer_pairs_, true);
   queue->Build(picture_layer_pairs_, tree_priority);
 }
 
 void LayerTreeHostImpl::BuildEvictionQueue(EvictionTilePriorityQueue* queue,
                                            TreePriority tree_priority) {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::BuildEvictionQueue");
   picture_layer_pairs_.clear();
-  GetPictureLayerImplPairs(&picture_layer_pairs_);
+  GetPictureLayerImplPairs(&picture_layer_pairs_, true);
   queue->Build(picture_layer_pairs_, tree_priority);
 }
 
 const std::vector<PictureLayerImpl*>& LayerTreeHostImpl::GetPictureLayers()
     const {
   return picture_layers_;
 }
 
 void LayerTreeHostImpl::NotifyReadyToActivate() {
   client_->NotifyReadyToActivate();
@@ skipping 2192 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