Add PictureLayerTiling pointer to Tile

cc/tiles/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/tiles/picture_layer_tiling.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <cmath>
@@ skipping 138 matching lines @@
 
   resolution_ = pending_twin->resolution_;
   bool create_missing_tiles = false;
   if (live_tiles_rect_.IsEmpty()) {
     live_tiles_rect_ = pending_twin->live_tiles_rect();
     create_missing_tiles = true;
   } else {
     SetLiveTilesRect(pending_twin->live_tiles_rect());
   }
 
-  if (tiles_.empty()) {
-    tiles_.swap(pending_twin->tiles_);
-    all_tiles_done_ = pending_twin->all_tiles_done_;
-  } else {
-    while (!pending_twin->tiles_.empty()) {
-      auto pending_iter = pending_twin->tiles_.begin();
-      tiles_[pending_iter->first] = std::move(pending_iter->second);
-      pending_twin->tiles_.erase(pending_iter);
-    }
-    all_tiles_done_ &= pending_twin->all_tiles_done_;
+  while (!pending_twin->tiles_.empty()) {
+    auto pending_iter = pending_twin->tiles_.begin();
+    pending_iter->second->set_tiling(this);
+    tiles_[pending_iter->first] = std::move(pending_iter->second);
+    pending_twin->tiles_.erase(pending_iter);
   }
+  all_tiles_done_ &= pending_twin->all_tiles_done_;
+
   DCHECK(pending_twin->tiles_.empty());
   pending_twin->all_tiles_done_ = true;
 
   if (create_missing_tiles)
     CreateMissingTilesInLiveTilesRect();
 
   VerifyLiveTilesRect(false);
 
   SetTilePriorityRects(pending_twin->current_content_to_screen_scale_,
                        pending_twin->current_visible_rect_,
@@ skipping 136 matching lines @@
         tile->SetInvalidated(invalid_content_rect, old_tile->id());
     }
   }
 }
 
 Tile::CreateInfo PictureLayerTiling::CreateInfoForTile(int i, int j) const {
   gfx::Rect tile_rect = tiling_data_.TileBoundsWithBorder(i, j);
   tile_rect.set_size(tiling_data_.max_texture_size());
   gfx::Rect enclosing_layer_rect = gfx::ScaleToEnclosingRect(
       tile_rect, 1.f / raster_scales_.width(), 1.f / raster_scales_.height());
-  return Tile::CreateInfo(i, j, enclosing_layer_rect, tile_rect,
+  return Tile::CreateInfo(this, i, j, enclosing_layer_rect, tile_rect,
                           raster_scales_);
 }
 
 bool PictureLayerTiling::ShouldCreateTileAt(
     const Tile::CreateInfo& info) const {
   const int i = info.tiling_i_index;
   const int j = info.tiling_j_index;
   // Active tree should always create a tile. The reason for this is that active
   // tree represents content that we draw on screen, which means that whenever
   // we check whether a tile should exist somewhere, the answer is yes. This
@@ skipping 628 matching lines @@
 size_t PictureLayerTiling::GPUMemoryUsageInBytes() const {
   size_t amount = 0;
   for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it) {
     const Tile* tile = it->second.get();
     amount += tile->GPUMemoryUsageInBytes();
   }
   return amount;
 }
 
 }  // namespace cc