Add mac UI for password generation

This is the Mac implementation of the password generation
(http://dev.chromium.org/developers/design-documents/password-generation).

Screenshot - http://oi49.tinypic.com/kcchz6.jpg
Windows UI (for comparison) - http://oi45.tinypic.com/51eauw.jpg

BUG=120776

Review URL: https://chromiumcodereview.appspot.com/11416047

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@172231 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/ui/browser_window.h b/chrome/browser/ui/browser_window.h
index 8b18627..75dc7d7 100644
--- a/chrome/browser/ui/browser_window.h
+++ b/chrome/browser/ui/browser_window.h
@@ -359,13 +359,11 @@
   // Show bubble for password generation positioned relative to |rect|. The
   // subclasses implementing this interface do not own the |password_generator|
   // object which is passed to generate the password. |form| is the form that
-  // contains the password field that the bubble will be associated with. A
-  // stub implementation is provided since this feature is currently not
-  // available on mac.
+  // contains the password field that the bubble will be associated with.
   virtual void ShowPasswordGenerationBubble(
       const gfx::Rect& rect,
       const content::PasswordForm& form,
-      autofill::PasswordGenerator* password_generator) {}
+      autofill::PasswordGenerator* password_generator) = 0;
 
  protected:
   friend void browser::CloseAllBrowsers();