Raster PictureLayerTiling with fractional translation

cc/layers/picture_layer_impl.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_LAYERS_PICTURE_LAYER_IMPL_H_
 #define CC_LAYERS_PICTURE_LAYER_IMPL_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 80 matching lines @@
 
   // Used for benchmarking
   RasterSource* GetRasterSource() const { return raster_source_.get(); }
 
   void set_is_directly_composited_image(bool is_directly_composited_image) {
     is_directly_composited_image_ = is_directly_composited_image;
   }
 
  protected:
   PictureLayerImpl(LayerTreeImpl* tree_impl, int id, bool is_mask);
-  PictureLayerTiling* AddTiling(float contents_scale);
+  PictureLayerTiling* AddTiling(float contents_scale,
+                                const gfx::Vector2dF& contents_translation);
   void RemoveAllTilings();
   void AddTilingsForRasterScale();
   void AddLowResolutionTilingIfNeeded();
   bool ShouldAdjustRasterScale() const;
+  void RecalculateRasterTranslation();
   void RecalculateRasterScales();
   void CleanUpTilingsOnActiveLayer(
       const std::vector<PictureLayerTiling*>& used_tilings);
   float MinimumContentsScale() const;
   float MaximumContentsScale() const;
   void ResetRasterScale();
   void UpdateViewportRectForTilePriorityInContentSpace();
   PictureLayerImpl* GetRecycledTwinLayer() const;
 
   void SanityCheckTilingState() const;
@@ skipping 16 matching lines @@
 
   float ideal_page_scale_;
   float ideal_device_scale_;
   float ideal_source_scale_;
   float ideal_contents_scale_;
 
   float raster_page_scale_;
   float raster_device_scale_;
   float raster_source_scale_;
   float raster_contents_scale_;
+  gfx::Vector2dF raster_contents_translation_;
   float low_res_raster_contents_scale_;
 
   bool was_screen_space_transform_animating_;
   bool only_used_low_res_last_append_quads_;
   const bool is_mask_;
 
   bool nearest_neighbor_;
   bool is_directly_composited_image_;
 
   // Use this instead of |visible_layer_rect()| for tiling calculations. This
   // takes external viewport and transform for tile priority into account.
   gfx::Rect viewport_rect_for_tile_priority_in_content_space_;
 
   gfx::Size gpu_raster_max_texture_size_;
 
   // List of tilings that were used last time we appended quads. This can be
   // used as an optimization not to remove tilings if they are still being
   // drawn. Note that accessing this vector should only be done in the context
   // of comparing pointers, since objects pointed to are not guaranteed to
   // exist.
   std::vector<PictureLayerTiling*> last_append_quads_tilings_;
 
   DISALLOW_COPY_AND_ASSIGN(PictureLayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_IMPL_H_