cc: Optimize decode scheduling for checker-images.

cc/tiles/tiling_set_raster_queue_all.cc

Index: cc/tiles/tiling_set_raster_queue_all.cc
diff --git a/cc/tiles/tiling_set_raster_queue_all.cc b/cc/tiles/tiling_set_raster_queue_all.cc
index 74bf1b2f144f806cadf802723924da96fc597f33..7fcca94c3e5ba00d7c4e39c28d874d3eef15323b 100644
--- a/cc/tiles/tiling_set_raster_queue_all.cc
+++ b/cc/tiles/tiling_set_raster_queue_all.cc
@@ -200,8 +200,14 @@ bool TilingSetRasterQueueAll::OnePriorityRectIterator::
 
 bool TilingSetRasterQueueAll::OnePriorityRectIterator::IsTileValid(
     const Tile* tile) const {
-  if (!tile || !TileNeedsRaster(tile))
+  if (!tile)
     return false;
+
+  bool should_process_tile_for_checker_imaging =
+      tile->is_checker_imaged() && tile->draw_info().requires_resource();
+  if (!TileNeedsRaster(tile) && !should_process_tile_for_checker_imaging)

[vmpstr, 2017/03/17 18:32:13]

TileNeedsRaster also has an occlusion check. I think that if the tile is
occluded then it shouldn't be processed for checker imaging either, so I think
you need to rework this a bit. 

[Khushal, 2017/03/27 13:57:33]

Done.

+    return false;
+
   // After the pending visible rect has been processed, we must return false
   // for pending visible rect tiles as tiling iterators do not ignore those
   // tiles.