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..a1dad22c4547728aa808a2eb0efcaf470b193337 100644
--- a/cc/tiles/tiling_set_raster_queue_all.cc
+++ b/cc/tiles/tiling_set_raster_queue_all.cc
@@ -200,8 +200,20 @@ bool TilingSetRasterQueueAll::OnePriorityRectIterator::
 
 bool TilingSetRasterQueueAll::OnePriorityRectIterator::IsTileValid(
     const Tile* tile) const {
-  if (!tile || !TileNeedsRaster(tile))
+  if (!tile)
     return false;
+
+  // Occluded tiles are not processed for raster or image decodes.
+  if (tiling_->IsTileOccluded(tile))
+    return false;
+
+  // If the tile does not need raster and does not have checkered-images
+  // requiring a decode, we don't need to add it to the raster queue.
+  if (!tile->draw_info().NeedsRaster() &&
+      !tile->draw_info().is_checker_imaged()) {
+    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.