Track occlusion per tree on Tile.

cc/resources/picture_layer_tiling.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/resources/picture_layer_tiling.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 
@@ skipping 477 matching lines @@
     bool is_occluded = false;
     if (occlusion_tracker) {
       gfx::Rect tile_query_rect = ScaleToEnclosingRect(
           IntersectRects(tile->content_rect(), visible_rect_in_content_space),
           1.0f / contents_scale_);
       // TODO(vmpstr): Remove render_target and draw_transform from the
       // parameters so they can be hidden from the tiling.
       is_occluded = occlusion_tracker->Occluded(
           render_target, tile_query_rect, draw_transform);
     }
-    tile->set_is_occluded(is_occluded);
+    tile->set_is_occluded(tree, is_occluded);
   }
 
   // Assign soon priority to skewport tiles.
   for (TilingData::DifferenceIterator iter(
            &tiling_data_, skewport, visible_rect_in_content_space);
        iter;
        ++iter) {
     TileMap::iterator find = tiles_.find(iter.index());
     if (find == tiles_.end())
       continue;
@@ skipping 464 matching lines @@
   tiling_->UpdateEvictionCacheIfNeeded(tree_priority_);
   tile_iterator_ = tiling_->eviction_tiles_cache_.begin();
   is_valid_ = true;
   if (tile_iterator_ != tiling_->eviction_tiles_cache_.end() &&
       !(*tile_iterator_)->HasResources()) {
     ++(*this);
   }
 }
 
 }  // namespace cc