Show notification instead of opening app launcher after extension installation

extensions/common/constants.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef EXTENSIONS_COMMON_CONSTANTS_H_
 #define EXTENSIONS_COMMON_CONSTANTS_H_
 
 #include "base/files/file_path.h"
 #include "ui/base/layout.h"
 
@@ skipping 112 matching lines @@
   SOURCE_SYSTEM_TRAY,
   SOURCE_ABOUT_PAGE,
   SOURCE_KEYBOARD,
   SOURCE_EXTENSIONS_PAGE,
   SOURCE_MANAGEMENT_API,
   SOURCE_EPHEMERAL_APP_DEPRECATED,
   SOURCE_BACKGROUND,
   SOURCE_KIOSK,
   SOURCE_CHROME_INTERNAL,
   SOURCE_TEST,
+  SOURCE_INSTALLED_NOTIFICATION,
 
   NUM_APP_LAUNCH_SOURCES
 };
 
 // This enum is used for the launch type the user wants to use for an
 // application.
 // Do not remove items or re-order this enum as it is used in preferences
 // and histograms.
 enum LaunchType {
   LAUNCH_TYPE_INVALID = -1,
@@ skipping 63 matching lines @@
 
 // The extension id for the production version of Hangouts.
 extern const char kProdHangoutsExtensionId[];
 
 // Extension ids used by Hangouts.
 extern const char* const kHangoutsExtensionIds[6];
 
 }  // namespace extension_misc
 
 #endif  // EXTENSIONS_COMMON_CONSTANTS_H_