In a small bowl let the porcini soak in 1 cup boiling water for 10 minutes, or until they are soft, and drain them well, reserving the liquid.
Season the chicken with pepper and dredge it in the flour, shaking off the excess.
In a large heavy skillet cook the bacon over moderate heat, stirring, until it is golden and crisp, transfer it with a slotted spoon to paper towels, and let it drain. Add to the skillet the chicken, skin side down, and cook it, turning it occasionally, for 20 minutes, or until it is golden and crisp. Transfer the chicken with a slotted spoon to a plate, season it with salt, and discard the fat in the skillet.
Add the oil to the skillet and in it cook the garlic over low heat, stirring for 1 minute. Add the reserved porcini liquid, the wine, the broth, and 3 tablespoons of the vinegar and boil the mixture for 4 minutes. Add the arrowroot mixture in a stream, stirring, stir in the tomatoes and add the chicken, turning it to coat it with the sauce. Simmer the mixture, covered, for 10 minutes, stir in the porcini and the bacon and simmer the mixture, covered, for 10 minutes. Stir in the remaining 1 tablespoon vinegar with salt and pepper to taste and sprinkle the mixture with the parsley.