Clear Search results in the Mac app launcher on close, rather than launch.

ui/app_list/cocoa/app_list_view_controller.h

Index: ui/app_list/cocoa/app_list_view_controller.h
diff --git a/ui/app_list/cocoa/app_list_view_controller.h b/ui/app_list/cocoa/app_list_view_controller.h
index 3573ab1264d5fd52c58ad4111c5bf0a85b76c024..e41a29fa7423bfc3426836bdea2925a97a0a07c7 100644
--- a/ui/app_list/cocoa/app_list_view_controller.h
+++ b/ui/app_list/cocoa/app_list_view_controller.h
@@ -51,6 +51,9 @@ APP_LIST_EXPORT
   BOOL showingSearchResults_;
 }
 
+@property(readonly, nonatomic) AppsSearchBoxController*
+    searchBoxController;
+
 - (app_list::AppListViewDelegate*)delegate;
 - (void)setDelegate:(scoped_ptr<app_list::AppListViewDelegate>)newDelegate;
 - (void)onSigninStatusChanged;
@@ -59,6 +62,8 @@ APP_LIST_EXPORT
 
 @interface AppListViewController (TestingAPI)
 
+@property(nonatomic, readonly) BOOL showingSearchResults;
+
 - (AppsGridController*)appsGridController;
 - (NSSegmentedControl*)pagerControl;
 - (NSView*)backgroundView;