Document who has access to the try server and commit queue
Document who has access to the try server and commit queue

Drop the text recommending the PolyGerrit UI, since it is now the
default Gerrit UI.

Bug: chromium:717982
Change-Id: I7041ee51670a7a18b510ed7a55045cc2eb09983e
Reviewed-on: https://chromium-review.googlesource.com/494726
Reviewed-by: Scott Graham <e134406e1863f3b48b0795831afac5c0595efb36@chromium.org>

chromium/crashpad,atom/crashpad,chromium/crashpad,atom/crashpad,chromium/crashpad,atom/crashpad