[MD settings] separate spacing of controlled-by icon and control-label
This CL replaces the use of the --cr-control-spacing with two variables
--cr--control-label-spacing and --cr-controlled-by-spacing. Those two
distances are now required (by UI) to be different values (20px and 24px
respectively). Removing the old variable and using more explicitly named
variables should help avoid confusion about where each should be used.
BUG=
721230
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
Review-Url:
https://codereview.chromium.org/2886603002
Cr-Commit-Position: refs/heads/master@{#472177}
Committed:
https://chromium.googlesource.com/chromium/src/+/38438a522f398efbc70717d69c8999fc13574640