Update dummy input generator

Author: simondanielsson

optimum/exporters/onnx/model_configs.py

@@ -506,13 +506,28 @@ class GemmaOnnxConfig(LlamaOnnxConfig):
     DUMMY_PKV_GENERATOR_CLASS = GemmaDummyPastKeyValuesGenerator
     MIN_TRANSFORMERS_VERSION = version.parse("4.38.0")
 
-@register_tasks_manager_onnx("gemma3", *[*COMMON_TEXT_GENERATION_TASKS, "text-classification"])
+
+@register_tasks_manager_onnx(
+    "gemma3", *[*COMMON_TEXT_GENERATION_TASKS, "text-classification"]
+)
 class Gemma3OnnxConfig(LlamaOnnxConfig):
-    DUMMY_INPUT_GENERATOR_CLASSES = (DummyTextInputGenerator, GemmaDummyPastKeyValuesGenerator)
+    DUMMY_INPUT_GENERATOR_CLASSES = (
+        DummyTextInputGenerator,
+        DummyVisionInputGenerator,
+    )
     DUMMY_PKV_GENERATOR_CLASS = GemmaDummyPastKeyValuesGenerator
     NORMALIZED_CONFIG_CLASS = NormalizedConfigManager.get_normalized_config_class("gemma3")
     MIN_TRANSFORMERS_VERSION = version.parse("4.52.0.dev0")
 
+    # TODO: check if we need this
+    # @property
+    # def inputs(self) -> dict[str, dict[int, str]]:
+    #     return {
+    #         "input_ids": {0: "batch_size", 1: "sequence_length"},
+    #         "attention_mask": {0: "batch_size", 1: "sequence_length"},
+    #         "pixel_values": {0: "batch_size", 1: "num_channels", 2: "image_size", 3: "image_size"},
+    #     }
+
 
 @register_tasks_manager_onnx("nemotron", *COMMON_TEXT_GENERATION_TASKS)
 class NemotronOnnxConfig(GemmaOnnxConfig):