cc: Remove tiles from recycle tree that were deleted on active.

cc/layers/picture_layer_impl.cc

 // Copyright 2012 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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/debug/trace_event_argument.h"
@@ skipping 42 matching lines @@
                              PictureLayerImpl* pending_layer)
     : active(active_layer), pending(pending_layer) {
 }
 
 PictureLayerImpl::Pair::~Pair() {
 }
 
 PictureLayerImpl::PictureLayerImpl(LayerTreeImpl* tree_impl, int id)
     : LayerImpl(tree_impl, id),
       twin_layer_(NULL),
+      recycled_twin_layer_(NULL),
       pile_(PicturePileImpl::Create()),
       is_mask_(false),
       ideal_page_scale_(0.f),
       ideal_device_scale_(0.f),
       ideal_source_scale_(0.f),
       ideal_contents_scale_(0.f),
       raster_page_scale_(0.f),
       raster_device_scale_(0.f),
       raster_source_scale_(0.f),
       raster_contents_scale_(0.f),
@@ skipping 29 matching lines @@
   // there are now tiles in this layer's tilings that were unref'd and replaced
   // with new tiles (due to invalidation). This resets all active priorities on
   // the to-be-recycled tiling to ensure replaced tiles don't linger and take
   // memory (due to a stale 'active' priority).
   if (layer_impl->tilings_)
     layer_impl->tilings_->DidBecomeRecycled();
 
   LayerImpl::PushPropertiesTo(base_layer);
 
   // When the pending tree pushes to the active tree, the pending twin
-  // disappears.
+  // becomes recycled.
   layer_impl->twin_layer_ = NULL;
+  layer_impl->recycled_twin_layer_ = this;
+  DCHECK(!recycled_twin_layer_);
   twin_layer_ = NULL;
 
   layer_impl->SetIsMask(is_mask_);
   layer_impl->pile_ = pile_;
 
   // Tilings would be expensive to push, so we swap.
   layer_impl->tilings_.swap(tilings_);
 
   // Remove invalidated tiles from what will become a recycle tree.
   if (tilings_)
@@ skipping 479 matching lines @@
     const PictureLayerTiling* tiling) const {
   if (!twin_layer_)
     return NULL;
   for (size_t i = 0; i < twin_layer_->tilings_->num_tilings(); ++i)
     if (twin_layer_->tilings_->tiling_at(i)->contents_scale() ==
         tiling->contents_scale())
       return twin_layer_->tilings_->tiling_at(i);
   return NULL;
 }
 
+PictureLayerTiling* PictureLayerImpl::GetRecycledTwinTiling(
+    const PictureLayerTiling* tiling) const {
+  if (!recycled_twin_layer_ || !recycled_twin_layer_->tilings_)
+    return NULL;
+  return recycled_twin_layer_->tilings_->TilingAtScale(
+      tiling->contents_scale());
+}
+
 size_t PictureLayerImpl::GetMaxTilesForInterestArea() const {
   return layer_tree_impl()->settings().max_tiles_for_interest_area;
 }
 
 float PictureLayerImpl::GetSkewportTargetTimeInSeconds() const {
   float skewport_target_time_in_frames =
       layer_tree_impl()->use_gpu_rasterization()
           ? kGpuSkewportTargetTimeInFrames
           : kCpuSkewportTargetTimeInFrames;
   return skewport_target_time_in_frames *
@@ skipping 316 matching lines @@
 
   if (!tilings_)
     tilings_.reset(new PictureLayerTilingSet(this, bounds()));
 
   DCHECK(!twin_layer_);
   twin_layer_ = static_cast<PictureLayerImpl*>(
       layer_tree_impl()->FindActiveTreeLayerById(id()));
   if (twin_layer_) {
     DCHECK(!twin_layer_->twin_layer_);
     twin_layer_->twin_layer_ = this;
+    twin_layer_->recycled_twin_layer_ = NULL;
     // If the twin has never been pushed to, do not sync from it.
     // This can happen if this function is called during activation.
     if (!twin_layer_->needs_post_commit_initialization_)
       SyncFromActiveLayer(twin_layer_);
   }
 
   needs_post_commit_initialization_ = false;
 }
 
 PictureLayerTiling* PictureLayerImpl::AddTiling(float contents_scale) {
@@ skipping 284 matching lines @@
     if (std::find(used_tilings.begin(), used_tilings.end(), tiling) !=
         used_tilings.end())
       continue;
 
     to_remove.push_back(tiling);
   }
 
   if (to_remove.empty())
     return;
 
-  PictureLayerImpl* recycled_twin = static_cast<PictureLayerImpl*>(
-      layer_tree_impl()->FindRecycleTreeLayerById(id()));
   // Remove tilings on this tree and the twin tree.
   for (size_t i = 0; i < to_remove.size(); ++i) {
     const PictureLayerTiling* twin_tiling = GetTwinTiling(to_remove[i]);
     // Only remove tilings from the twin layer if they have
     // NON_IDEAL_RESOLUTION.
     if (twin_tiling && twin_tiling->resolution() == NON_IDEAL_RESOLUTION)
       twin->RemoveTiling(to_remove[i]->contents_scale());
     // Remove the tiling from the recycle tree. Note that we ignore resolution,
     // since we don't need to maintain high/low res on the recycle tree.
-    if (recycled_twin)
-      recycled_twin->RemoveTiling(to_remove[i]->contents_scale());
+    if (recycled_twin_layer_)
+      recycled_twin_layer_->RemoveTiling(to_remove[i]->contents_scale());
     // TODO(enne): temporary sanity CHECK for http://crbug.com/358350
     CHECK_NE(HIGH_RESOLUTION, to_remove[i]->resolution());
     tilings_->Remove(to_remove[i]);
   }
 
   DCHECK_GT(tilings_->num_tilings(), 0u);
   SanityCheckTilingState();
 }
 
 float PictureLayerImpl::MinimumContentsScale() const {
@@ skipping 472 matching lines @@
       PictureLayerTilingSet::TilingRange tiling_range = CurrentTilingRange();
       size_t current_tiling_range_offset = current_tiling_ - tiling_range.start;
       return tiling_range.end - 1 - current_tiling_range_offset;
     }
   }
   NOTREACHED();
   return 0;
 }
 
 }  // namespace cc