cc: Indicate that we've updated a tiling if we invalidated it.

cc/tiles/picture_layer_tiling.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TILES_PICTURE_LAYER_TILING_H_
 #define CC_TILES_PICTURE_LAYER_TILING_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 385 matching lines @@
   gfx::Rect current_eventually_rect_;
   // Other properties used for tile iteration and prioritization.
   float current_content_to_screen_scale_;
   Occlusion current_occlusion_in_layer_space_;
 
   bool has_visible_rect_tiles_;
   bool has_skewport_rect_tiles_;
   bool has_soon_border_rect_tiles_;
   bool has_eventually_rect_tiles_;
   bool all_tiles_done_;
+  bool invalidated_since_last_compute_priority_rects_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PictureLayerTiling);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_PICTURE_LAYER_TILING_H_