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..86d435f3eba487112cbc9b184b09ffe1757855d0 100644
--- a/cc/resources/picture_layer_tiling.cc
+++ b/cc/resources/picture_layer_tiling.cc
@@ -57,6 +57,14 @@ class TileEvictionOrder {
  private:
   TreePriority tree_priority_;
 };
+
+// Reset priority as tile is ref-counted and might still be used
+// even though we no longer hold a reference to it here anymore.

[reveman, 2014/07/28 15:50:53]

Please move this comment just above "tile->SetPriority(..." below

[sohanjg, 2014/07/30 11:12:57]

Done.

+void ResetPriority(Tile* tile, WhichTree tree) {

[reveman, 2014/07/28 15:50:53]

I would prefer if you named this "ReleaseTile" and resetting priority is a
implementation detail of it.

[sohanjg, 2014/07/30 11:12:57]

Done.

+  DCHECK(tile);

[reveman, 2014/07/28 15:50:53]

Remove this. It's awkward to not be able to assume that |tile| != NULL in a
function that takes a Tile as its main parameter. If you need to DCHECK |tile|,
do it before calling this function instead. Not sure it's needed though.

[sohanjg, 2014/07/30 11:12:57]

Acknowledged.

+  tile->SetPriority(tree, TilePriority());
+}
+
 }  // namespace
 
 scoped_ptr<PictureLayerTiling> PictureLayerTiling::Create(
@@ -94,6 +102,8 @@ PictureLayerTiling::PictureLayerTiling(float contents_scale,
 }
 
 PictureLayerTiling::~PictureLayerTiling() {
+  for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it)
+    ResetPriority(it->second.get(), client_->GetTree());
 }
 
 void PictureLayerTiling::SetClient(PictureLayerTilingClient* client) {
@@ -214,6 +224,9 @@ void PictureLayerTiling::DoInvalidate(const Region& layer_region,
       TileMap::iterator find = tiles_.find(key);
       if (find == tiles_.end())
         continue;
+
+      ResetPriority(find->second.get(), client_->GetTree());
+
       tiles_.erase(find);
       new_tile_keys.push_back(key);
     }
@@ -598,8 +611,10 @@ 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()) {
+      ResetPriority(found->second.get(), client_->GetTree());
       tiles_.erase(found);
+    }
   }
 
   const PictureLayerTiling* twin_tiling = client_->GetTwinTiling(this);