Add a very basic preferences window controller with unit test. Fix the prefs ...

chrome/browser/cocoa/preferences_window_controller.h

Index: chrome/browser/cocoa/preferences_window_controller.h
===================================================================
--- chrome/browser/cocoa/preferences_window_controller.h	(revision 0)
+++ chrome/browser/cocoa/preferences_window_controller.h	(revision 0)
@@ -0,0 +1,21 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <Cocoa/Cocoa.h>
+
+class PrefService;
+
+// A window controller that handles the preferences window.
+@interface PreferencesWindowController : NSWindowController {
+ @private
+  PrefService* prefs_;  // weak ref
+}
+
+// Designated initializer. |prefs| should not be NULL.
+- (id)initWithPrefs:(PrefService*)prefs;
+
+// Show the preferences window.
+- (IBAction)showPreferences:(id)sender;
+
+@end