Clip to clip_rect instead of paint bounds (flutter#8183)

Otherwise, we'll have issues such as flutter/flutter#29070

The engine roll that includes this PR needs a tiny golden image update. Will do a manual roll.

flow/layers/clip_rect_layer.cc

@@ -48,10 +48,10 @@ void ClipRectLayer::Paint(PaintContext& context) const {
   FML_DCHECK(needs_painting());
 
   SkAutoCanvasRestore save(context.internal_nodes_canvas, true);
-  context.internal_nodes_canvas->clipRect(paint_bounds(),
+  context.internal_nodes_canvas->clipRect(clip_rect_,
                                           clip_behavior_ != Clip::hardEdge);
   if (clip_behavior_ == Clip::antiAliasWithSaveLayer) {
-    context.internal_nodes_canvas->saveLayer(paint_bounds(), nullptr);
+    context.internal_nodes_canvas->saveLayer(clip_rect_, nullptr);
   }
   PaintChildren(context);
   if (clip_behavior_ == Clip::antiAliasWithSaveLayer) {