Add TransformFeedback related APIs to command buffer: PART I.

gpu/command_buffer/service/gles2_cmd_validation_autogen.h

Index: gpu/command_buffer/service/gles2_cmd_validation_autogen.h
diff --git a/gpu/command_buffer/service/gles2_cmd_validation_autogen.h b/gpu/command_buffer/service/gles2_cmd_validation_autogen.h
index 0418ad088370cbe3f0fa6e83c51364916b86b61b..fc650d2287c1fb01f64243f6087ef9729ebcd227 100644
--- a/gpu/command_buffer/service/gles2_cmd_validation_autogen.h
+++ b/gpu/command_buffer/service/gles2_cmd_validation_autogen.h
@@ -70,6 +70,8 @@ ValueValidator<GLenum> texture_pool;
 ValueValidator<GLenum> texture_target;
 ValueValidator<GLenum> texture_usage;
 ValueValidator<GLenum> texture_wrap_mode;
+ValueValidator<GLenum> transform_feedback_bind_target;
+ValueValidator<GLenum> transform_feedback_primitive_mode;
 ValueValidator<GLenum> value_buffer_target;
 ValueValidator<GLint> vertex_attrib_size;
 ValueValidator<GLenum> vertex_attrib_type;