Add ES3 commands GetVertexAttribI{u}iv to GPU command buffer.

gpu/command_buffer/build_gles2_cmd_buffer.py

Index: gpu/command_buffer/build_gles2_cmd_buffer.py
diff --git a/gpu/command_buffer/build_gles2_cmd_buffer.py b/gpu/command_buffer/build_gles2_cmd_buffer.py
index b1c8ee12558d970e488875b6a153adb91e9f21f9..67f77f845261b00f427e3016c2780c2149b4361c 100755
--- a/gpu/command_buffer/build_gles2_cmd_buffer.py
+++ b/gpu/command_buffer/build_gles2_cmd_buffer.py
@@ -2918,6 +2918,24 @@ _FUNCTION_INFO = {
     'expectation': False,
     'client_test': False,
   },
+  'GetVertexAttribIiv': {
+    'type': 'GETn',
+    'result': ['SizedResult<GLint>'],
+    'impl_decl': False,
+    'decoder_func': 'DoGetVertexAttribIiv',
+    'expectation': False,
+    'client_test': False,
+    'unsafe': True,
+  },
+  'GetVertexAttribIuiv': {
+    'type': 'GETn',
+    'result': ['SizedResult<GLuint>'],
+    'impl_decl': False,
+    'decoder_func': 'DoGetVertexAttribIuiv',
+    'expectation': False,
+    'client_test': False,
+    'unsafe': True,
+  },
   'GetVertexAttribPointerv': {
     'type': 'Custom',
     'data_transfer_methods': ['shm'],