Roll mini_chromium a12ed4a6..20182dd2
Roll mini_chromium a12ed4a6..20182dd2

$ git log --oneline a12ed4a6..20182dd2
20182dd Add missing newline at EOF after d1943e187f47
d1943e1 Add a stub for Chromium's base::UmaHistogramSparse().
9920849 gn, mac: Various GN build fixes
0b16698 gn, mac: Tell libtool not to warn about empty .o files

R=f1b5a91d4d6ad523f2610114591c007e75d15084@chromium.org

Bug: chromium:773850
Change-Id: I2fb4b7ed8a8efa8b3d37f1b8f131396e9a2bbfdc
Reviewed-on: https://chromium-review.googlesource.com/827648
Reviewed-by: Mark Mentovai <f1b5a91d4d6ad523f2610114591c007e75d15084@chromium.org>

chromium/crashpad,chromium/crashpad,chromium/crashpad