[4/5] Add translated rasterization support for PictureLayerTilingSet & below

cc/tiles/picture_layer_tiling_set.cc

 // 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.
 
 #include "cc/tiles/picture_layer_tiling_set.h"
 
 #include <stddef.h>
 
 #include <limits>
 #include <set>
@@ skipping 65 matching lines @@
   if (pending_twin_set->tilings_.empty()) {
     // If the twin (pending) tiling set is empty, it was not updated for the
     // current frame. So we drop tilings from our set as well, instead of
     // leaving behind unshared tilings that are all non-ideal.
     RemoveAllTilings();
     return;
   }
 
   bool tiling_sort_required = false;
   for (const auto& pending_twin_tiling : pending_twin_set->tilings_) {
+    ScaleTranslate2d raster_transform = pending_twin_tiling->raster_transform();
     PictureLayerTiling* this_tiling =
         FindTilingWithScaleKey(pending_twin_tiling->contents_scale_key());
+    if (this_tiling && this_tiling->raster_transform() != raster_transform) {

[enne (OOO), 2017/01/03 22:53:53]

This could use some unit testing too.

[trchen, 2017/03/28 21:44:01]

Done.

+      Remove(this_tiling);
+      this_tiling = nullptr;
+    }
     if (!this_tiling) {
       std::unique_ptr<PictureLayerTiling> new_tiling(new PictureLayerTiling(
-          tree_, pending_twin_tiling->raster_scales(), raster_source_, client_,
+          tree_, raster_transform, raster_source_, client_,
           kMaxSoonBorderDistanceInScreenPixels, max_preraster_distance_));
       tilings_.push_back(std::move(new_tiling));
       this_tiling = tilings_.back().get();
       tiling_sort_required = true;
       state_since_last_tile_priority_update_.added_tilings = true;
     }
     this_tiling->TakeTilesAndPropertiesFrom(pending_twin_tiling.get(),
                                             layer_invalidation);
   }
 
@@ skipping 162 matching lines @@
                      });
   tilings_.erase(to_remove, tilings_.end());
 }
 
 void PictureLayerTilingSet::MarkAllTilingsNonIdeal() {
   for (const auto& tiling : tilings_)
     tiling->set_resolution(NON_IDEAL_RESOLUTION);
 }
 
 PictureLayerTiling* PictureLayerTilingSet::AddTiling(
-    float contents_scale_key,
+    const ScaleTranslate2d& raster_transform,
     scoped_refptr<RasterSource> raster_source) {
   if (!raster_source_)
     raster_source_ = raster_source;
 
 #if DCHECK_IS_ON()
   for (size_t i = 0; i < tilings_.size(); ++i) {
-    DCHECK_NE(tilings_[i]->contents_scale_key(), contents_scale_key);
+    DCHECK_NE(tilings_[i]->contents_scale_key(), raster_transform.scale());
     DCHECK_EQ(tilings_[i]->raster_source(), raster_source.get());
   }
 #endif  // DCHECK_IS_ON()
 
-  gfx::SizeF raster_scales(contents_scale_key,
-                           contents_scale_key / aspect_ratio_);
   tilings_.push_back(base::MakeUnique<PictureLayerTiling>(
-      tree_, raster_scales, raster_source, client_,
+      tree_, raster_transform, raster_source, client_,
       kMaxSoonBorderDistanceInScreenPixels, max_preraster_distance_));
   PictureLayerTiling* appended = tilings_.back().get();
   state_since_last_tile_priority_update_.added_tilings = true;
 
   std::sort(tilings_.begin(), tilings_.end(), LargestToSmallestScaleFunctor());
   return appended;
 }
 
 int PictureLayerTilingSet::NumHighResTilings() const {
   return std::count_if(tilings_.begin(), tilings_.end(),
@@ skipping 77 matching lines @@
       snapped_ratio = ratio;
     }
   }
   return snapped_contents_scale;
 }
 
 float PictureLayerTilingSet::GetMaximumContentsScale() const {
   if (tilings_.empty())
     return 0.f;
   // The first tiling has the largest contents scale.
-  return std::max(tilings_[0]->raster_scales().width(),
-                  tilings_[0]->raster_scales().height());
+  return tilings_[0]->raster_transform().scale();
 }
 
 bool PictureLayerTilingSet::TilingsNeedUpdate(
     const gfx::Rect& visible_rect_in_layer_space,
     double current_frame_time_in_seconds) {
   // If we don't have any tilings, we don't need an update.
   if (num_tilings() == 0)
     return false;
 
   // If we never updated the tiling set, then our history is empty. We should
@@ skipping 385 matching lines @@
     case LOWER_THAN_LOW_RES:
       range = TilingRange(low_res_range.end, tilings_size);
       break;
   }
 
   DCHECK_LE(range.start, range.end);
   return range;
 }
 
 }  // namespace cc