Raster PictureLayerTiling with fractional translation

cc/tiles/tile_manager.cc

Index: cc/tiles/tile_manager.cc
diff --git a/cc/tiles/tile_manager.cc b/cc/tiles/tile_manager.cc
index ed30f468df20d007e762e907d9af49c54afd01d3..df3ffa2a47e5cf38e26914fa960aae472d85352f 100644
--- a/cc/tiles/tile_manager.cc
+++ b/cc/tiles/tile_manager.cc
@@ -62,7 +62,7 @@ class RasterTaskImpl : public TileTask {
         raster_source_(std::move(raster_source)),
         content_rect_(tile->content_rect()),
         invalid_content_rect_(invalidated_rect),
-        contents_scale_(tile->contents_scale()),
+        contents_transform_(tile->contents_transform()),
         playback_settings_(playback_settings),
         tile_resolution_(tile_resolution),
         layer_id_(tile->layer_id()),
@@ -91,7 +91,7 @@ class RasterTaskImpl : public TileTask {
 
     raster_buffer_->Playback(raster_source_.get(), content_rect_,
                              invalid_content_rect_, new_content_id_,
-                             contents_scale_, playback_settings_);
+                             contents_transform_, playback_settings_);
   }
 
   // Overridden from TileTask:
@@ -125,7 +125,7 @@ class RasterTaskImpl : public TileTask {
   scoped_refptr<RasterSource> raster_source_;
   gfx::Rect content_rect_;
   gfx::Rect invalid_content_rect_;
-  float contents_scale_;
+  ScaleTranslate2d contents_transform_;
   RasterSource::PlaybackSettings playback_settings_;
   TileResolution tile_resolution_;
   int layer_id_;
@@ -641,9 +641,11 @@ TileManager::PrioritizedWorkToSchedule TileManager::AssignGpuMemoryToTiles() {
       // TODO(sohanjg): Check if we could use a shared analysis
       // canvas which is reset between tiles.
       SkColor color = SK_ColorTRANSPARENT;
+      gfx::RectF layer_rect = tile->contents_transform().TransformReverse(
+          gfx::RectF(tile->content_rect()));
       bool is_solid_color =
           prioritized_tile.raster_source()->PerformSolidColorAnalysis(
-              tile->content_rect(), tile->contents_scale(), &color);
+              gfx::ToEnclosingRect(layer_rect), 1.f, &color);
       if (is_solid_color) {
         tile->draw_info().set_solid_color(color);
         tile->draw_info().set_was_ever_ready_to_draw();
@@ -844,7 +846,8 @@ void TileManager::ScheduleTasks(
 
     std::vector<DrawImage> images;
     prioritized_tile.raster_source()->GetDiscardableImagesInRect(
-        tile->enclosing_layer_rect(), tile->contents_scale(), &images);
+        tile->enclosing_layer_rect(), tile->contents_transform().pre_scale(),
+        &images);
     ImageDecodeController::TracingInfo tracing_info(
         prepare_tiles_count_, prioritized_tile.priority().priority_bin);
     for (DrawImage& draw_image : images) {
@@ -960,7 +963,8 @@ scoped_refptr<TileTask> TileManager::CreateRasterTask(
   images.clear();
   if (!playback_settings.skip_images) {
     prioritized_tile.raster_source()->GetDiscardableImagesInRect(
-        tile->enclosing_layer_rect(), tile->contents_scale(), &images);
+        tile->enclosing_layer_rect(), tile->contents_transform().pre_scale(),
+        &images);
   }
 
   // We can skip the image hijack canvas if we have no images.