cc: Do not cleanup tiles with raster tasks.

cc/resources/picture_layer_tiling.cc

Index: cc/resources/picture_layer_tiling.cc
diff --git a/cc/resources/picture_layer_tiling.cc b/cc/resources/picture_layer_tiling.cc
index fdfbad9f62e3e60bbd1949541123ef36c5713de1..87e264b471c413e96023188999d4b6aa1ea0a602 100644
--- a/cc/resources/picture_layer_tiling.cc
+++ b/cc/resources/picture_layer_tiling.cc
@@ -94,6 +94,11 @@ PictureLayerTiling::PictureLayerTiling(float contents_scale,
 }
 
 PictureLayerTiling::~PictureLayerTiling() {
+  for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it) {
+    Tile* tile = it->second.get();
+    tile->SetPriority(ACTIVE_TREE, TilePriority());
+    tile->SetPriority(PENDING_TREE, TilePriority());

[reveman, 2014/07/24 13:36:24]

I don't think you can reset both pending and active priority here. What about
the twin tiling that might be alive and using one of these?

[sohanjg, 2014/07/24 15:01:55]

If we reset the priority of only the pending tree here,
how do we reset for the active tree before we drop the tile ?
Vlad , enne ?

[vmpstr, 2014/07/24 16:19:21]

Since at this point the tile can be shared on both trees, you should only reset
the priority of the tree that it's on. You might have to add WhichTree
PictureLayerTilingClient::GetTree(); and then do 

tile->SetPriority(client_->GetTree(), TilePriority());

If the tile is released into tile manager that means one of two things: 1. It
wasn't shared, in which case the other priority wasn't ever set or 2. both trees
released it, which means you would get two of these tilings releasing the same
tile with a different client_->GetTree value.

(I mean this is the reason that I was OK with clearing it in tile manager: it's
just a final stop for the tile... here works as well, but it's a bit more work).

[sohanjg, 2014/07/25 09:38:26]

Done.

+  }
 }
 
 void PictureLayerTiling::SetClient(PictureLayerTilingClient* client) {
@@ -214,6 +219,13 @@ void PictureLayerTiling::DoInvalidate(const Region& layer_region,
       TileMap::iterator find = tiles_.find(key);
       if (find == tiles_.end())
         continue;
+
+      // Reset priority as tile is ref-counted and might still be used
+      // even though we no longer hold a reference to it here anymore.
+      Tile* tile = find->second.get();
+      tile->SetPriority(ACTIVE_TREE, TilePriority());
+      tile->SetPriority(PENDING_TREE, TilePriority());

[reveman, 2014/07/24 13:36:24]

same here. resetting both active and pending priority seems wrong.

[sohanjg, 2014/07/25 09:38:26]

Done.

+
       tiles_.erase(find);
       new_tile_keys.push_back(key);
     }
@@ -598,8 +610,12 @@ void PictureLayerTiling::SetLiveTilesRect(
     TileMap::iterator found = tiles_.find(key);
     // If the tile was outside of the recorded region, it won't exist even
     // though it was in the live rect.
-    if (found != tiles_.end())
+    if (found != tiles_.end()) {
+      Tile* tile = found->second.get();
+      tile->SetPriority(ACTIVE_TREE, TilePriority());
+      tile->SetPriority(PENDING_TREE, TilePriority());

[reveman, 2014/07/24 13:36:24]

and here. resetting both active and pending priority seems wrong.

[sohanjg, 2014/07/25 09:38:26]

Done.

       tiles_.erase(found);
+    }
   }
 
   const PictureLayerTiling* twin_tiling = client_->GetTwinTiling(this);