Mac: Style the omnibox URL.

Mac: Style the omnibox URL.

Cribbed this mostly from GTK, including taking their colors pretty
directly.  The hostname in the URL is a stronger color than the rest
of the URL to call it out.  The https: scheme is also called out
specially.  The background color changes when secure.

Also cleaned up the selection-setting so that there are distinct code
paths for updating the field and setting the selection.

Also fixed saving of selection across popup navigation via arrow keys.

Also sprinkled some const jimmies while I was in there.

http://crbug.com/10939
TEST=Type an URL, does the hostname highlight versus the rest?  Do secure URLS look different?

[Scott Hess - ex-Googler, 2009-05-15 21:20:44]

Tossing this at you because you complained about focus-stealing.  If this helps,
it wasn't the original intent, but styling at the right points seemed to want
selecting at the right points, and I suspect that's where much of the
focus-stealing is coming from.

[Avi (use Gerrit), 2009-05-15 21:45:53]

The code LG. This doesn't fix the focus stealing, though.

[Scott Hess - ex-Googler, 2009-05-15 22:29:47]

On 2009/05/15 21:45:53, Avi wrote:
> The code LG. This doesn't fix the focus stealing, though.

Darn.  Now I have no reason to not buckle down and poke at that bug.