Implement Mac pref-pane UI mockups

Implement Mac pref-pane UI mockups

This updates the screens to match the mockups.  There are two
new nib files.  One is a view with just a disable button.  The
other is a view with the PIN-confirmation controls.  The main
nib has been updated to remove all controls except for the
Status text and the padlock.  A new placeholder box has been
added in the middle of the window, which can show either of
the new nibs, depending on whether a new config has been
received by the pref-pane.

This also fixes some small issues:

PIN is reset whenever a new config is sent to the pref-pane -
this prevents the previous PIN dots being shown if the user
changes PIN a second time without closing the System Preferences
applet.

The PIN entry box is disabled until the pane is unlocked, for a
slightly improved UX.


BUG=128813, 129032
TEST=manual

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=138322

[Lambros, 2012-05-18 23:05:00]

I have no idea what's going on with Rietveld and the new nibs.  They are
brand-view files, but Patch Set 1 is showing them as modified, with phantom
diffs.

[dcaiafa, 2012-05-21 15:45:30]

http://codereview.chromium.org/10411032/diff/1/remoting/host/me2me_preference...
File remoting/host/me2me_preference_pane.mm (right):

http://codereview.chromium.org/10411032/diff/1/remoting/host/me2me_preference...
remoting/host/me2me_preference_pane.mm:157: confirm_pin_view_ =
[[Me2MePreferencePaneConfirmPin alloc] init];
Leak in non-GC environment. I'd move the alloc/inits to the init method, and
place releases in the dealloc method.

[Jamie, 2012-05-22 17:01:00]

LGTM, but Daniel's GC comment is worth fixing in a follow-up CL.