Does a failure to instruct on "heat of passion" voluntary manslaughter constitute a lesser included crime of murder?

^3. We acknowledge that recently, People v. Thomas (2013) 218 Cal.App.4th 630 held that a failure to instruct on "heat of passion" voluntary manslaughter as a lesser included offense of murder violates the federal constitution. (Id. at pp. 643-644.) It reasoned that heat of passion negates malice, and malice is a necessary element of murder; thus, failure to instruct on heat of passion unconstitutionally lessens the prosecution's burden of proving every element of the charged crime. (Id. at p. 644.)