cc: Reset tile priority before deleting tiling.

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 40ac4d55a03228d7c55d42ae793479757e9209a4..b11e4569e2ec4097525708e50d86cc128e4740e2 100644
--- a/cc/resources/picture_layer_tiling.cc
+++ b/cc/resources/picture_layer_tiling.cc
@@ -49,6 +49,8 @@ PictureLayerTiling::PictureLayerTiling(float contents_scale,
 }
 
 PictureLayerTiling::~PictureLayerTiling() {
+  for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it)
+    client_->DestroyTile(it->second);
 }
 
 void PictureLayerTiling::SetClient(PictureLayerTilingClient* client) {
@@ -267,6 +269,8 @@ gfx::Size PictureLayerTiling::CoverageIterator::texture_size() const {
 
 void PictureLayerTiling::Reset() {
   live_tiles_rect_ = gfx::Rect();
+  for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it)
+    client_->DestroyTile(it->second);
   tiles_.clear();
 }
 
@@ -438,6 +442,7 @@ void PictureLayerTiling::SetLiveTilesRect(
     // though it was in the live rect.
     if (found == tiles_.end())
       continue;
+    client_->DestroyTile(found->second);
     tiles_.erase(found);
   }