Deleted AppListViewDelegateObserver class (was unused).

ui/app_list/test/app_list_test_view_delegate.cc

Index: ui/app_list/test/app_list_test_view_delegate.cc
diff --git a/ui/app_list/test/app_list_test_view_delegate.cc b/ui/app_list/test/app_list_test_view_delegate.cc
index d4c57302dd98531da4ed9eccab1530c08ee35668..443724bb3972bd0bd85a91d7752f99dc33308109 100644
--- a/ui/app_list/test/app_list_test_view_delegate.cc
+++ b/ui/app_list/test/app_list_test_view_delegate.cc
@@ -11,7 +11,6 @@
 #include "base/files/file_path.h"
 #include "ui/app_list/app_list_model.h"
 #include "ui/app_list/app_list_switches.h"
-#include "ui/app_list/app_list_view_delegate_observer.h"
 #include "ui/app_list/test/app_list_test_model.h"
 #include "ui/gfx/image/image_skia.h"
 
@@ -105,15 +104,5 @@ void AppListTestViewDelegate::ReplaceTestModel(int item_count) {
   model_->PopulateApps(item_count);
 }
 
-void AppListTestViewDelegate::AddObserver(
-    AppListViewDelegateObserver* observer) {
-  observers_.AddObserver(observer);
-}
-
-void AppListTestViewDelegate::RemoveObserver(
-    AppListViewDelegateObserver* observer) {
-  observers_.RemoveObserver(observer);
-}
-
 }  // namespace test
 }  // namespace app_list