A unified analysis of four cosmic shear surveys by Chang, C, Wang, M, Dodelson, S, Eifler, T, Heymans, C, Jarvis, M, Jee, MJ, Joudaki, S, Krause, E, Malz, A, Mandelbaum, R, Mohammed, I, Schneider, M, Simet, M, Troxel, MA, Zuntz, J, LSST Dark Energy Sci Collaboration