cc: Optimize decode scheduling for checker-images.

cc/tiles/tile.h

Index: cc/tiles/tile.h
diff --git a/cc/tiles/tile.h b/cc/tiles/tile.h
index 16d37d1491d88a5f9b7938eada47ed21ea32d2d2..83414f54028b51081998a1e4f25e23ed44efe052 100644
--- a/cc/tiles/tile.h
+++ b/cc/tiles/tile.h
@@ -10,6 +10,7 @@
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "cc/paint/draw_image.h"
 #include "cc/raster/tile_task.h"
 #include "cc/tiles/tile_draw_info.h"
 #include "ui/gfx/geometry/rect.h"
@@ -113,6 +114,29 @@ class CC_EXPORT Tile {
     return is_solid_color_analysis_performed_;
   }
 
+  void SetImageAnalysisResult(
+      std::vector<DrawImage> images_to_decode_before_raster,
+      std::vector<sk_sp<const SkImage>> images_to_checker);
+  bool is_image_analysis_performed() const {
+    return is_image_analysis_performed_;
+  }
+  const std::vector<DrawImage>& images_to_decode_before_raster() const {
+    return images_to_decode_before_raster_;
+  }
+  const std::vector<sk_sp<const SkImage>>& images_to_checker() const {
+    return images_to_checker_;
+  }
+
+  bool set_raster_task_scheduled_with_checker_images(bool has_checker_images) {
+    bool previous_raster_task_scheduled_with_checker_images =
+        raster_task_scheduled_with_checker_images_;
+    raster_task_scheduled_with_checker_images_ = has_checker_images;
+    return previous_raster_task_scheduled_with_checker_images;
+  }
+  bool raster_task_scheduled_with_checker_images() const {
+    return raster_task_scheduled_with_checker_images_;
+  }
+
   const PictureLayerTiling* tiling() const { return tiling_; }
   void set_tiling(const PictureLayerTiling* tiling) { tiling_ = tiling; }
 
@@ -134,6 +158,18 @@ class CC_EXPORT Tile {
   const gfx::Rect enclosing_layer_rect_;
   const float contents_scale_;
 
+  // Image analysis is used partitions the images in a tile into 2 sets:
+  // 1) The images for which the decode must be available *before* the
+  //    rasterization of a tile can be started.
+  // 2) The images which are checkered, i.e., will be skipped when rasterizing
+  //    this tile.
+  // Note that these sets are only valid for tiles that are considered for
+  // rasterization with images. For instance, for low resolution tiles, all
+  // images are skipped.
+  bool is_image_analysis_performed_ = false;
+  std::vector<DrawImage> images_to_decode_before_raster_;
+  std::vector<sk_sp<const SkImage>> images_to_checker_;
+
   TileDrawInfo draw_info_;
 
   const int layer_id_;
@@ -154,6 +190,10 @@ class CC_EXPORT Tile {
   Id invalidated_id_;
 
   unsigned scheduled_priority_;
+
+  // Set to true if there is a raster task scheduled for this tile that will
+  // rasterize a resource with checker images.
+  bool raster_task_scheduled_with_checker_images_ = false;
   scoped_refptr<TileTask> raster_task_;
 
   DISALLOW_COPY_AND_ASSIGN(Tile);