cc: Merge LayerTree into the LayerTreeHost.

cc/layers/picture_layer.cc

Index: cc/layers/picture_layer.cc
diff --git a/cc/layers/picture_layer.cc b/cc/layers/picture_layer.cc
index 625fca6378fb8ae76bf27f302e0660adaf98286c..9a5acf514b247ecb596d436b5e9e54bfd44adf90 100644
--- a/cc/layers/picture_layer.cc
+++ b/cc/layers/picture_layer.cc
@@ -60,7 +60,7 @@ void PictureLayer::PushPropertiesTo(LayerImpl* base_layer) {
   scoped_refptr<RasterSource> raster_source =
       recording_source_->CreateRasterSource(can_use_lcd_text);
   layer_impl->set_gpu_raster_max_texture_size(
-      GetLayerTree()->device_viewport_size());
+      layer_tree_host()->device_viewport_size());
   layer_impl->UpdateRasterSource(raster_source, &last_updated_invalidation_,
                                  nullptr);
   DCHECK(last_updated_invalidation_.IsEmpty());
@@ -83,7 +83,7 @@ void PictureLayer::SetLayerTreeHost(LayerTreeHost* host) {
 }
 
 void PictureLayer::SetNeedsDisplayRect(const gfx::Rect& layer_rect) {
-  DCHECK(!layer_tree_host() || !GetLayerTree()->in_paint_layer_contents());
+  DCHECK(!layer_tree_host() || !layer_tree_host()->in_paint_layer_contents());
   if (recording_source_)
     recording_source_->SetNeedsDisplayRect(layer_rect);
   Layer::SetNeedsDisplayRect(layer_rect);