cc: Do the math for a tile's content rect in layer space once.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index ddb7b04bf186bb5b576e95d9fc918ea983b3ab17..4f15794c4f6884aac39279ae452cd34cf3133df5 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -627,8 +627,7 @@ Region PictureLayerImpl::GetInvalidationRegion() {
   return IntersectRegions(invalidation_, update_rect());
 }
 
-ScopedTilePtr PictureLayerImpl::CreateTile(float contents_scale,
-                                           const gfx::Rect& content_rect) {
+ScopedTilePtr PictureLayerImpl::CreateTile(const Tile::CreateInfo& info) {
   int flags = 0;
 
   // We don't handle solid color masks, so we shouldn't bother analyzing those.
@@ -637,8 +636,7 @@ ScopedTilePtr PictureLayerImpl::CreateTile(float contents_scale,
     flags = Tile::USE_PICTURE_ANALYSIS;
 
   return layer_tree_impl()->tile_manager()->CreateTile(
-      content_rect.size(), content_rect, contents_scale, id(),
-      layer_tree_impl()->source_frame_number(), flags);
+      info, id(), layer_tree_impl()->source_frame_number(), flags);
 }
 
 const Region* PictureLayerImpl::GetPendingInvalidation() {