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

ui/app_list/cocoa/app_list_window_controller.mm

Index: ui/app_list/cocoa/app_list_window_controller.mm
diff --git a/ui/app_list/cocoa/app_list_window_controller.mm b/ui/app_list/cocoa/app_list_window_controller.mm
index 47edab050747daf1be4e5a738d5aeddbd5f6c311..0da462d928bb40d010a2ca2eacd2f800e6f1bc66 100644
--- a/ui/app_list/cocoa/app_list_window_controller.mm
+++ b/ui/app_list/cocoa/app_list_window_controller.mm
@@ -7,6 +7,7 @@
 #include "ui/app_list/app_list_view_delegate.h"
 #import "ui/app_list/cocoa/app_list_view_controller.h"
 #import "ui/app_list/cocoa/apps_grid_controller.h"
+#import "ui/app_list/cocoa/apps_search_box_controller.h"
 #include "ui/base/cocoa/window_size_constants.h"
 
 @interface AppListWindow : NSWindow;
@@ -59,4 +60,8 @@
     [appListViewController_ delegate]->Dismiss();
 }
 
+- (void)windowWillClose:(NSNotification*)notification {
+  [[appListViewController_ searchBoxController] clearSearch];
+}
+
 @end