[Mac] Convert omnibox keyword hint to decoration.

[Mac] Convert omnibox keyword hint to decoration.

Additionally, convert to use more basic drawing rather than
NSAttributedString, to save needing the text-attachment class.  Strip
out all of the unit-test code relating to decoration exclusion, as
those cases are no longer possible in those ways.

BUG=none
TEST=Browse to www.google.com.  Command-l, type google and should see "Press [tab] to search Google".
TEST=Should have I-beam cursor over the "Press ..." phrase.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=52928

[Scott Hess - ex-Googler, 2010-07-17 06:01:30]

Last bit, now everything is a decoration.

[Scott Hess - ex-Googler, 2010-07-17 06:03:00]

On 2010/07/17 06:01:30, shess wrote:
> Last bit, now everything is a decoration.

And sorry about the lateness.  Waited for the tree to open so I could get
everything else checked in, rather than put up something with notable loose
ends.

[rohitrao (ping after 24h), 2010-07-19 16:57:33]

LGTM.  Nice to see all that code go.

It occurs to me that AutocompleteTextFieldCell no longer really does anything
autocomplete-specific :)

http://codereview.chromium.org/2854051/diff/1/7
File chrome/browser/cocoa/location_bar/keyword_hint_decoration.mm (right):

http://codereview.chromium.org/2854051/diff/1/7#newcode34
chrome/browser/cocoa/location_bar/keyword_hint_decoration.mm:34: NSDictionary* d
=
Call this "attributes" instead of "d."

[Scott Hess - ex-Googler, 2010-07-19 17:52:12]

On 2010/07/19 16:57:33, rohitrao wrote:
> LGTM.  Nice to see all that code go.
> 
> It occurs to me that AutocompleteTextFieldCell no longer really does anything
> autocomplete-specific :)

Just need to find somewhere else to use all of this black magic.

[Maybe findbar, but at some point I'm not sure whether the similarities _really_
outweigh the differences.  It wouldn't surprise me much to determine that we
could fork the two uses again and reduce the overall amount of code :-).]

http://codereview.chromium.org/2854051/diff/1/7
File chrome/browser/cocoa/location_bar/keyword_hint_decoration.mm (right):

http://codereview.chromium.org/2854051/diff/1/7#newcode34
chrome/browser/cocoa/location_bar/keyword_hint_decoration.mm:34: NSDictionary* d
=
On 2010/07/19 16:57:33, rohitrao wrote:
> Call this "attributes" instead of "d."

Done.