Move occlusion info to TilePriority.

cc/resources/tile.cc

Index: cc/resources/tile.cc
diff --git a/cc/resources/tile.cc b/cc/resources/tile.cc
index 781d00899e13935ee458a7c6cef28c082d17c273..0a604e901c9861d95b018769386cc33077575ce0 100644
--- a/cc/resources/tile.cc
+++ b/cc/resources/tile.cc
@@ -30,7 +30,6 @@ Tile::Tile(TileManager* tile_manager,
       content_rect_(content_rect),
       contents_scale_(contents_scale),
       opaque_rect_(opaque_rect),
-      is_occluded_(false),
       layer_id_(layer_id),
       source_frame_number_(source_frame_number),
       flags_(flags),
@@ -60,6 +59,14 @@ void Tile::MarkRequiredForActivation() {
   tile_manager_->DidChangeTilePriority(this);
 }
 
+void Tile::SetIsOccluded(WhichTree tree, bool occluded) {
+  if (priority_[tree].is_occluded == occluded)
+    return;
+
+  priority_[tree].is_occluded = occluded;
+  tile_manager_->DidChangeTilePriority(this);
+}
+
 scoped_ptr<base::Value> Tile::AsValue() const {
   scoped_ptr<base::DictionaryValue> res(new base::DictionaryValue());
   TracedValue::MakeDictIntoImplicitSnapshotWithCategory(