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

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 0ec80686b8dc87069fd123bd1cb5cffb7084c3ef..dd39587cbba0a1c6851653e46701adb4649959c5 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -60,6 +60,7 @@ 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),
@@ -109,8 +110,10 @@ void PictureLayerImpl::PushPropertiesTo(LayerImpl* base_layer) {
   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_);
@@ -610,6 +613,14 @@ const PictureLayerTiling* PictureLayerImpl::GetTwinTiling(
   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;
 }
@@ -946,6 +957,7 @@ void PictureLayerImpl::DoPostCommitInitialization() {
   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_)
@@ -1250,8 +1262,6 @@ void PictureLayerImpl::CleanUpTilingsOnActiveLayer(
   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]);
@@ -1261,8 +1271,8 @@ void PictureLayerImpl::CleanUpTilingsOnActiveLayer(
       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]);