notification balloons: Remove views and cocoa implementations of BalloonCollection.

chrome/browser/notifications/notification_ui_manager.cc

Index: chrome/browser/notifications/notification_ui_manager.cc
diff --git a/chrome/browser/notifications/notification_ui_manager.cc b/chrome/browser/notifications/notification_ui_manager.cc
index 84fe1aa8d1d5a8e1ef232a387d55448b6b68a160..c4e841f103ddc745a8dbf9b3613ace01686f1694 100644
--- a/chrome/browser/notifications/notification_ui_manager.cc
+++ b/chrome/browser/notifications/notification_ui_manager.cc
@@ -41,19 +41,13 @@ NotificationUIManager* NotificationUIManager::Create(PrefService* local_state) {
         settings_provider.Pass());
   }
 
-#if defined(OS_CHROMEOS)
-  // Since we can't reach here for CrOS (see above), no point compiling all
-  // the dependent classes there.
-  CHECK(false);
-  return NULL;
-#elif defined(OS_MACOSX) || defined(USE_AURA)
-  // IsRichNotificationEnabled() always returns true in this case.
-  CHECK(false);
-  return NULL;
-#else
+#if defined(TOOLKIT_GTK)
   BalloonNotificationUIManager* balloon_manager =
       new BalloonNotificationUIManager(local_state);
   balloon_manager->SetBalloonCollection(BalloonCollection::Create());
   return balloon_manager;
+#else
+  CHECK(false);
+  return NULL;
 #endif
 }