Sorry, didn't get any pictures with more of the plant (but potentially could). Approximately 2m tall cultivated shrub in Southern California.
Judging by the little I can see of the foliage, which appears to be greyish and downy, its not Hibiscus, its one of the shrubby mallows - in this case, the most likely is Lavatera maritima 'bicolour', sometimes commonly called Tree Mallow. The flowers of lavateras are similar to Hibiscus, but Hibiscus syriacus flowers much later on in summer, and the foliage is different - thinner leaves which are green, not greyish green and slightly felty or woolly.
Growth is usually cut right down in autumn or spring in the northern hemisphere, and in colder climates, it may die over winter, and may be shortlived. Prefers a sheltered sunny spot, free draining soil, and, as its name implies, does well in coastal regions.