YouTube once funded creator-driven original content — but the streaming giant wound that down several years ago and instead embarked on a strategy to promote shows YouTubers are already producing themselves. That makes YouTube an outlier during TV upfronts week: It’s making an ad pitch to Madison Avenue on content it doesn’t directly control or finance. At its YouTube Brandcast in New York Wednesday, the Google-owned platform is doubling down on the strategy. At the heart of its presentation is