fuchsia: Set METRICS_OS_NAME
fuchsia: Set METRICS_OS_NAME

Bug: crashpad:196
Change-Id: I4f01c4f04c94a745b4c30bc41f66d2ae010e883a
Reviewed-on: https://chromium-review.googlesource.com/786817
Commit-Queue: Scott Graham <e134406e1863f3b48b0795831afac5c0595efb36@chromium.org>
Reviewed-by: Mark Mentovai <f1b5a91d4d6ad523f2610114591c007e75d15084@chromium.org>

chromium/crashpad,chromium/crashpad,chromium/crashpad