[rAC, OSX] Stop suggestions/inputs from flickering

Stop visual dialog flicker when switching a section's input source from
manual to suggestions or vice versa.

1) Coalesce "requestRelayout" messages, so they are only called once
   the current RunLoop iteration is done. Previously, they were
   executed immediately on each individual data change - multiple times
   while the controller was updating.

2) Change visibility of suggestions/inputs _after_ the views have been
   laid out. Prevents briefly observable layout flow.

NOTRY=true
BUG=286530

Review URL: https://codereview.chromium.org/25358002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226375 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226375
[rAC, OSX] saveInChrome status now persistent.

The AutofillDialogController already persisted the state of the
"Save in Chrome" checkbox. This CL ensures that the OSX dialog reflects
that persisted state and is properly updated when the state changes.

NOTRY=true
BUG=282101
R=avi@chromium.org

Review URL: https://codereview.chromium.org/25405003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226376 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226376