Sky: different tack for custom Rect type in the Canvas API.

sky/engine/bindings/scripts/dart_types.py

Index: sky/engine/bindings/scripts/dart_types.py
diff --git a/sky/engine/bindings/scripts/dart_types.py b/sky/engine/bindings/scripts/dart_types.py
index 83335aa40ed1acfc46735c3b18dc023e3aeb4cbb..2a063b87a59b9bcdc8a8ba7c7beead79be6f7ca1 100644
--- a/sky/engine/bindings/scripts/dart_types.py
+++ b/sky/engine/bindings/scripts/dart_types.py
@@ -114,6 +114,7 @@ CPP_SPECIAL_CONVERSION_RULES = {
     'boolean': 'bool',
     'unrestricted double': 'double',
     'unrestricted float': 'float',
+    'Rect': 'Rect',  # Pass Rect by value, not pointer.
 }
 
 
@@ -352,6 +353,7 @@ DART_TO_CPP_VALUE = {
     # FIXME(vsm): This is an enum type (defined in StorageQuota.idl).
     # We should handle it automatically, but map to a String for now.
     'StorageType': 'DartUtilities::dartToString(args, {index}, exception, {auto_scope})',
+    'Rect': 'DartConverter<{implemented_as}>::FromArguments{null_check}(args, {index}, exception)',
 }