What is the de novo standard of review applied to a failure to instruct on a lesser included offence?

The de novo standard of review is applied to the failure to instruct on a lesser included offense. (People v. Cole (2004) 33 Cal.4th 1158, 1218.) If a trial court fails to instruct on a lesser included offense that is supported by the evidence, the error is one of state law alone. (People v. Breverman, supra, 19 Cal.4th at p. 165.) Such an error does not require reversal unless "an examination of the entire record establishes a reasonable probability that the error affected the outcome." (Ibid.)