Raster PictureLayerTiling with fractional translation

cc/tiles/tile.h

Index: cc/tiles/tile.h
diff --git a/cc/tiles/tile.h b/cc/tiles/tile.h
index 76142e86699118f284d0e11acb86aba35ad80348..7fa7c1a0fb2dda6b5fb1c68664b05b35435b3cea 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/base/scale_translate2d.h"
 #include "cc/raster/tile_task.h"
 #include "cc/tiles/tile_draw_info.h"
 #include "ui/gfx/geometry/rect.h"
@@ -34,18 +35,18 @@ class CC_EXPORT Tile {
     int tiling_j_index;
     gfx::Rect enclosing_layer_rect;
     gfx::Rect content_rect;
-    float contents_scale;
+    ScaleTranslate2d contents_transform;
 
     CreateInfo(int tiling_i_index,
                int tiling_j_index,
                const gfx::Rect& enclosing_layer_rect,
                const gfx::Rect& content_rect,
-               float contents_scale)
+               const ScaleTranslate2d& contents_transform)
         : tiling_i_index(tiling_i_index),
           tiling_j_index(tiling_j_index),
           enclosing_layer_rect(enclosing_layer_rect),
           content_rect(content_rect),
-          contents_scale(contents_scale) {}
+          contents_transform(contents_transform) {}
   };
 
   enum TileRasterFlags { USE_PICTURE_ANALYSIS = 1 << 0, IS_OPAQUE = 1 << 1 };
@@ -77,7 +78,10 @@ class CC_EXPORT Tile {
   const TileDrawInfo& draw_info() const { return draw_info_; }
   TileDrawInfo& draw_info() { return draw_info_; }
 
-  float contents_scale() const { return contents_scale_; }
+  //  float contents_scale() const { return contents_scale_; }
+  const ScaleTranslate2d& contents_transform() const {
+    return contents_transform_;
+  }
   const gfx::Rect& content_rect() const { return content_rect_; }
   const gfx::Rect& enclosing_layer_rect() const {
     return enclosing_layer_rect_;
@@ -123,7 +127,7 @@ class CC_EXPORT Tile {
   TileManager* const tile_manager_;
   const gfx::Rect content_rect_;
   const gfx::Rect enclosing_layer_rect_;
-  const float contents_scale_;
+  const ScaleTranslate2d contents_transform_;
 
   TileDrawInfo draw_info_;