Cut ancho chilies in half lengthwise; seed and stem. Heat heavy large skillet over medium-high heat; add chilies and stir until chilies look dry and darken slightly in color, turning occasionally, about 2 1/2 minutes. Cool completely. Break chilies into 1/2-inch pieces. Grind coarsely in spice mill or coffee mill. Add oregano and grind to blend. Transfer to small bowl. Mix in salt and sugar. Stir in garlic, chipotle chilies, and lime juice. Whisk in oil. Add enough water to thin to spreadable consistency (about 1 tablespoon). (Can be prepared 3 days ahead. Cover and chill.).
Preheat oven to 400°F Spread 2 generous teaspoons chili mixture over each salmon fillet. Place on rimmed baking sheet. Bake until salmon is opaque in center, about 10 minutes.