[librsvg: 80/90] Move the decision about the topmost temporary surface to CompositingAffines::new

[Federico Mena Quintero <federico src gnome org>]

commit e8f979141f83ceb4198f12c2fbd57b48af4e7e1e
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri Mar 22 11:01:27 2019 -0600

    Move the decision about the topmost temporary surface to CompositingAffines::new

 rsvg_internals/src/drawing_ctx.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/rsvg_internals/src/drawing_ctx.rs b/rsvg_internals/src/drawing_ctx.rs
index 50f693ba..acc3df9d 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -465,12 +465,10 @@ impl DrawingCtx {
                 if needs_temporary_surface {
                     // Compute our assortment of affines
 
-                    let is_topmost_temporary_surface = dc.cr_stack.len() == 0;
-
                     let affines = CompositingAffines::new(
                         affine_at_start,
                         dc.initial_affine_with_offset(),
-                        is_topmost_temporary_surface,
+                        dc.cr_stack.len(),
                     );
 
                     // Create temporary surface and its cr
@@ -910,8 +908,10 @@ impl CompositingAffines {
     fn new(
         current: cairo::Matrix,
         initial: cairo::Matrix,
-        is_topmost_temporary_surface: bool,
+        cr_stack_depth: usize,
     ) -> CompositingAffines {
+        let is_topmost_temporary_surface = cr_stack_depth == 0;
+
         let initial_inverse = initial.try_invert().unwrap();
 
         let affine = if is_topmost_temporary_surface {