[NTP4] Experiment for adding Chrome Web Store link to footer.

chrome/common/extensions/extension_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 CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_
 #pragma once
 
 #include <string>
 
@@ skipping 428 matching lines @@
     APP_LAUNCH_NTP_WEBSTORE,
 
     // App launched after the user re-enabled it on the NTP.
     APP_LAUNCH_NTP_APP_RE_ENABLE,
 
     // URL launched using the --app cmd line option, but the URL does not
     // correspond to an installed app. These launches are left over from a
     // feature that let you make desktop shortcuts from the file menu.
     APP_LAUNCH_CMD_LINE_APP_LEGACY,
 
+    // User clicked web store link on the NTP footer.
+    APP_LAUNCH_NTP_WEBSTORE_FOOTER,
+
     APP_LAUNCH_BUCKET_BOUNDARY,
     APP_LAUNCH_BUCKET_INVALID
   };
 
 #if defined(OS_CHROMEOS)
   // The directory path on a ChromeOS device where accessibility extensions are
   // stored.
   extern const char kAccessExtensionPath[];
   extern const char kChromeVoxDirectoryName[];
 #endif
@@ skipping 11 matching lines @@
 
   enum UnloadedExtensionReason {
     UNLOAD_REASON_DISABLE,    // Extension is being disabled.
     UNLOAD_REASON_UPDATE,     // Extension is being updated to a newer version.
     UNLOAD_REASON_UNINSTALL,  // Extension is being uninstalled.
     UNLOAD_REASON_TERMINATE,  // Extension has terminated.
   };
 }  // extension_misc
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_