cc: ReadyToDraw notifications.

cc/resources/tile.h

Index: cc/resources/tile.h
diff --git a/cc/resources/tile.h b/cc/resources/tile.h
index c6413677eb9cff8a8d506c80722705060ddd904e..042d5aeb570d8f5573563f6103a95a6c17e31aaa 100644
--- a/cc/resources/tile.h
+++ b/cc/resources/tile.h
@@ -85,6 +85,10 @@ class CC_EXPORT Tile : public RefCountedManaged<Tile> {
   void set_required_for_activation(bool is_required) {
     required_for_activation_ = is_required;
   }
+  bool required_for_draw() const { return required_for_draw_; }
+  void set_required_for_draw(bool is_required) {
+    required_for_draw_ = is_required;
+  }
 
   bool use_picture_analysis() const {
     return !!(flags_ & USE_PICTURE_ANALYSIS);
@@ -174,6 +178,7 @@ class CC_EXPORT Tile : public RefCountedManaged<Tile> {
   int tiling_i_index_;
   int tiling_j_index_;
   bool required_for_activation_;
+  bool required_for_draw_;
 
   Id id_;
   static Id s_next_id_;