canvas: pop many clips on restore (#38496)

When restoring context/state we need to pop all clips from current
state, before we just poped one (even if there was none).

Testing: Added new WPT tests

---------

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

components/canvas/canvas_data.rs

@@ -749,8 +749,10 @@ impl<DrawTarget: GenericDrawTarget> CanvasData<DrawTarget> {
         }
     }
 
-    pub(crate) fn pop_clip(&mut self) {
-        self.drawtarget.pop_clip();
+    pub(crate) fn pop_clips(&mut self, clips: usize) {
+        for _ in 0..clips {
+            self.drawtarget.pop_clip();
+        }
     }
 }